Types of modern lithium batteries. Lithium-ion and lithium-polymer batteries

Among the most modern batteries, lithium ones occupy a special place. In chemistry, lithium is the most active metal.

It has a huge energy storage resource. 1 kg of lithium can store 3860 ampere hours. The well-known zinc lags far behind. His figure is 820 ampere-hours.

Lithium-based cells can produce voltages up to 3.7V. But laboratory samples are capable of producing a voltage of about 4.5V.

Modern lithium batteries do not use pure lithium.

There are currently 3 common types of lithium batteries:

Lithium-ion ( Li-ion). Rated voltage (U nom.) - 3.6V;

Lithium polymer ( Li-Po, Li-polymer or "lipo"). U nom. - 3.7V;

Lithium iron phosphate ( Li-Fe or LFP ). U nom. - 3.3V.

All these types of lithium batteries differ in the cathode or electrolyte material. Li-ion uses a lithium cobaltate cathode LiCoO2, Li-Po uses a gel polymer electrolyte, and Li-Fe uses a lithium ferrophosphate cathode LiFePO 4.

Any lithium battery (or the device in which it operates) is equipped with a small electronic circuit - a charge/discharge controller. Since lithium-based batteries are very sensitive to overcharging and deep discharge, this is necessary. If you pick apart any lithium battery from a cell phone, you can find a small electronic circuit in it - this is the protective controller ( Protection IC ).

If there is no built-in controller (or charge supervisor) in a lithium battery, then such a battery is called unprotected. In this case, the controller is built into the device, which is powered by such a battery, and charging is possible only from the device or from a special charger.

The photo shows an unprotected Li-Po battery Turnigy 2200 mAh 3C 25C Lipo Pack. This battery consists of 3 cells connected in series (3C - 3 cell) of 3.7V each and therefore has a balancing connector. The continuous discharge current can reach 25C, i.e. 25 * 2200 mA = 55000 mA = 55 A! And the short-term discharge current (10 sec.) is 35C!

Lithium batteries, which consist of several cells connected in series, require a complex charger equipped with a balancer. This functionality is implemented, for example, in such universal chargers as Turnigy Accucell 6 and IMAX B6.

A balancer is needed to equalize the voltage across individual cells during charging of a composite lithium battery. Due to differences between cells, some may charge faster and others slower. Therefore, a special circuit for shunting the charging current is used.

This is the wiring for the balancing and power cables of an 11.1V LiPo battery.

As is known, overcharging a lithium battery cell (especially Li-Polymer) above 4.2V can lead to an explosion or spontaneous combustion. Therefore, during charging it is necessary to control the voltage on each cell compound battery battery!

Correct charging of lithium batteries.

Lithium batteries (Li-ion, Li-Po, Li-Fe) are charged according to the CC/CV method (“constant current/constant voltage”). The method is that first, when the voltage on the element is low, it is charged with a constant current of a certain value. When the voltage on the cell reaches (for example, up to 4.2V - depends on the type of battery), the charge controller maintains a constant voltage across it.

First stage lithium battery charge - CC- implemented through feedback. The controller selects the voltage on the element so that the charge current is strictly constant.

During the first charging stage, the lithium battery accumulates most of the power (60 - 80%).

Second stage charge - CV- begins when the voltage on the element reaches a certain threshold level (for example, 4.2V). After this, the controller simply maintains a constant voltage on the element and gives it the current it needs. Towards the end of the charge, the current decreases to 30 - 10 mA. At this current, the element is considered charged.

During the second stage, the battery accumulates the remaining 40 - 20% of the power.

It is worth noting that exceeding the threshold voltage on a lithium battery can cause it to overheat and even explode!

When charging lithium batteries, it is recommended to place them in a fireproof bag. This is especially true for batteries that do not have a special box. For example, those that are used in radio-controlled models (car, aircraft modeling).

Disadvantages of lithium-ion batteries.

The main and most frightening disadvantage of lithium-based batteries is their fire hazard if the operating voltage is exceeded, overheating, improper charging and illiterate operation. There are especially many complaints regarding lithium-polymer (Li-Polymer) batteries. However, lithium iron phosphate (Li-Fe) batteries do not have such a negative feature - they are fireproof.

Also, lithium batteries are very afraid of the cold - they quickly lose their capacity and stop charging. This applies to Li-ion and Li-Po batteries. Lithium iron phosphate (Li-Fe) batteries are more resistant to frost. Actually, this is one of the positive qualities of Li-Fe batteries.

The disadvantage of lithium batteries is that they require a special charge controller - an electronic circuit. And in the case of a composite battery and balancer.

When deeply discharged, lithium batteries lose their original properties. Li-ion and Li-Po batteries are especially susceptible to deep discharge. Even after restoration, such a battery will have a lower capacity.

If a lithium battery does not “work” for a long time, then first the voltage on it will drop to a threshold level (usually 3.2-3.3V). The electronic circuit will completely turn off the battery cell, and then a deep discharge will begin. If the voltage on the cell drops to 2.5V, this can lead to its failure.

Therefore, it is worth recharging the batteries of laptops, cell phones, and mp3 players from time to time during long periods of inactivity.

Typically, the service life of an ordinary lithium battery is 3 - 5 years. After 3 years, the battery capacity begins to decrease quite noticeably.

Reading “tips for operating” batteries on forums, you can’t help but think - either people skipped physics and chemistry at school, or they think that the rules for operating lead-acid and ion batteries are the same.
Let's start with the principles of operation of a Li-Ion battery. On the fingers, everything is extremely simple - there is a negative electrode (usually made of copper), there is a positive one (made of aluminum), between them there is a porous substance (separator) impregnated with electrolyte (it prevents the “unauthorized” transfer of lithium ions between the electrodes):

The principle of operation is based on the ability of lithium ions to be integrated into the crystal lattice of various materials - usually graphite or silicon oxide - with the formation of chemical bonds: accordingly, when charging, the ions are built into the crystal lattice, thereby accumulating a charge on one electrode, and when discharging, they respectively move back to the other electrode , giving away the electron we need (who is interested in a more accurate explanation of the processes taking place - google intercalation). Water-containing solutions that do not contain a free proton and are stable over a wide voltage range are used as electrolytes. As you can see, in modern batteries everything is done quite safely - there is no lithium metal, there is nothing to explode, only ions run through the separator.
Now that everything has become more or less clear about the operating principle, let’s move on to the most common myths about Li-Ion batteries:

Myth one. The Li-Ion battery in the device cannot be discharged to zero percent.
In fact, everything sounds correct and is consistent with physics - when discharged to ~2.5 V, the Li-Ion battery begins to degrade very quickly, and even one such discharge can significantly (up to 10%!) reduce its capacity. In addition, if the voltage is discharged to such a voltage with a standard charger, it will no longer be possible to charge it - if the battery cell voltage drops below ~3 V, the “smart” controller will turn it off as damaged, and if there are all such cells, the battery can be taken to the trash.
But there is one very important thing that everyone forgets: in phones, tablets and other mobile devices, the operating voltage range on the battery is 3.5-4.2 V. When the voltage drops below 3.5 V, the indicator shows zero percent charge and the device turns off, but before " critical" 2.5 V is still very far away. This is confirmed by the fact that if you connect an LED to such a “discharged” battery, it can remain on for a long time (maybe someone remembers that they used to sell phones with flashlights that were turned on by a button regardless of the system. So the light there continued to burn even after discharge and turn off the phone). That is, as you can see, during normal use, discharge to 2.5 V does not occur, which means it is quite possible to discharge the battery to zero percent.
Myth two. If Li-Ion batteries are damaged, they explode.
We all remember the “explosive” Samsung Galaxy Note 7. However, this is rather an exception to the rule - yes, lithium is a very active metal, and it is not difficult to explode it in the air (and it burns very brightly in water). However, modern batteries do not use lithium, but its ions, which are much less active. So for an explosion to occur, you need to try very hard - either physically damage the charging battery (cause a short circuit), or charge it with a very high voltage (then it will be damaged, but most likely the controller will simply burn out itself and will not allow the battery to charge). Therefore, if you suddenly have a damaged or smoking battery in your hands, do not throw it on the table and run away from the room shouting “we are all going to die” - just put it in a metal container and take it out to the balcony (so as not to breathe in the chemicals) - the battery will smolder for some time and then go out. The main thing is not to fill it with water, the ions are of course less active than lithium, but still some amount of hydrogen will also be released when reacting with water (and it likes to explode).
Myth three. When a Li-Ion battery reaches 300 (500/700/1000/100500) cycles, it becomes unsafe and needs to be replaced urgently.
A myth, fortunately, that circulates less and less on forums and has no physical or chemical explanation at all. Yes, during operation, the electrodes oxidize and corrode, which reduces the battery capacity, but this does not threaten you with anything other than shorter battery life and unstable behavior at 10-20% charge.
Myth four. Li-Ion batteries cannot be used in the cold.
This is more of a recommendation than a prohibition. Many manufacturers prohibit the use of phones at sub-zero temperatures, and many have experienced rapid discharge and even shutdown of phones in the cold. The explanation for this is very simple: the electrolyte is a water-containing gel, and everyone knows what happens to water at subzero temperatures (yes, it freezes, if anything), thereby rendering some area of the battery unusable. This leads to a voltage drop, and the controller begins to consider this a discharge. This is not beneficial for the battery, but it is not fatal either (after heating, the capacity will return), so if you desperately need to use the phone in the cold (to use it - take it out of a warm pocket, check the time and put it back does not count) then it is better to charge it 100% and turn on any process that loads the processor - this will cool it down more slowly.
Myth fifth. A swollen Li-Ion battery is dangerous and should be thrown away immediately.
This is not exactly a myth, but rather a precaution - a swollen battery can simply burst. From a chemical point of view, everything is simple: during the intercalation process, the electrodes and electrolyte decompose, resulting in the release of gas (it can also be released during recharging, but more on that below). But very little of it is released, and for the battery to appear swollen, several hundred (if not thousands) of recharge cycles must go through (unless, of course, it is defective). There are no problems getting rid of the gas - just pierce the valve (in some batteries it opens itself when there is excess pressure) and bleed it off (I don’t recommend breathing with it), after which you can cover the hole with epoxy resin. Of course, this will not return the battery to its former capacity, but at least now it will definitely not burst.
Myth six. Overcharging is harmful to Li-Ion batteries.
But this is no longer a myth, but a harsh reality - when recharging, there is a high chance that the battery will swell, burst and catch fire - believe me, there is little pleasure in being splashed with boiling electrolyte. Therefore, all batteries have controllers that simply prevent the battery from being charged above a certain voltage. But here you need to be extremely careful in choosing a battery - Chinese handicraft controllers can often malfunction, and I don’t think fireworks from your phone at 3 am will make you happy. Of course, the same problem exists in branded batteries, but firstly, this happens much less often there, and secondly, they will replace your entire phone under warranty. This myth usually gives rise to the following:
Myth seventh. When you reach 100%, you need to remove the phone from charging.
From the sixth myth, this seems reasonable, but in reality there is no point in getting up in the middle of the night and unplugging the device: firstly, controller failures are extremely rare, and secondly, even when the indicator reaches 100%, the battery still charges for some time to the very, very maximum low currents, which adds another 1-3% capacity. So, in reality, you shouldn’t play it safe.
Myth eight. You can charge the device only with the original charger.
The myth exists due to the poor quality of Chinese chargers - at a normal voltage of 5 +- 5% volts they can produce both 6 and 7 - the controller, of course, will smooth out this voltage for some time, but in the future it will, at best, lead to to the controller burning out, at worst - to an explosion and (or) failure of the motherboard. The opposite also happens - under load, the Chinese charger produces 3-4 volts: this will lead to the battery not being able to charge completely.

As can be seen from a whole bunch of misconceptions, not all of them have a scientific explanation, and even fewer actually worsen the performance of batteries. But this does not mean that after reading my article you need to run headlong and buy cheap Chinese batteries for a couple of bucks - nevertheless, for longevity, it is better to take either the original ones or high-quality copies of the original ones.

Modern mobile phones, cameras and other devices most often use lithium-ion batteries, replacing alkaline and nickel-cadmium batteries, which they are superior to in many respects. Batteries with a lithium anode first appeared in the 70s of the previous century and immediately became very popular due to their high voltage and energy intensity.

History of appearance

The developments were short-lived, but difficulties arose at the practical level that were resolved only in the 90s of the last century. Due to the high activity of lithium, chemical processes occurred inside the element, which led to fire.

In the early 90s, a number of accidents occurred - telephone users, while talking, received severe burns as a result of spontaneous ignition of the elements, and then of the communication devices themselves. In this regard, the batteries were completely discontinued and previously released ones were returned from sale.

Modern lithium-ion batteries do not use pure metal, only its ionized compounds, as they are more stable. Unfortunately, scientists had to significantly reduce the battery's capabilities, but they managed to achieve the main thing - people no longer suffered from burns.

The crystal lattice of various carbon compounds was found to be suitable for the intercalation of lithium ions at the negative electrode. When charging, they move from the anode to the cathode, and when discharging, vice versa.

Operating principle and varieties

In every lithium-ion battery, the basis of the negative electrode is carbon-containing substances, the structure of which can be ordered or partially ordered. Depending on the material, the process of intercalation of Li into C varies. The positive electrode is mainly made of plated nickel or cobalt oxide.

Summarizing all reactions, they can be represented in the following equations:

LiCoO2 → Li1-xCoO2 + xLi+ + xe - for the cathode.
C + xLi+ + xe → CLix - for the anode.

The equations are presented for the case of discharge; during charging they flow in the opposite direction. Scientists are conducting research into new materials consisting of mixed phosphates and oxides. These materials are planned to be used for the cathode.

There are two types of Li-Ion batteries:

cylindrical;
prismatic.

The main difference is the location of the plates (in prismatic - on top of each other). The size of the lithium battery depends on this. As a rule, prismatic ones are denser and more compact.

In addition, there is a safety system inside - a mechanism that, when the temperature increases, increases the resistance, and when the pressure increases, it breaks the anode-cathode circuit. Thanks to the electronic board, a short circuit becomes impossible, since it controls the processes inside the battery.

Electrodes of opposite polarity are separated by a separator. The case must be sealed; leakage of electrolyte or ingress of water and oxygen will destroy both the battery and the electronic carrier device itself.

From different manufacturers, a lithium battery may look completely different; there is no uniform product shape. The ratio of the active masses of the anode to the cathode should be approximately 1:1, otherwise the formation of lithium metal is possible, which will lead to fire.

Advantages and disadvantages

Batteries have excellent parameters that differ from one manufacturer to another. The nominal voltage is 3.7−3.8 V with a maximum of 4.4 V. Energy density (one of the main indicators) is 110−230 Wh/kg.

Internal resistance ranges from 5 to 15 mOhm/1Ah. The service life by the number of cycles (discharge/charge) is 1000−5000 units. Fast charging time is 15−60 minutes. One of the most significant advantages is the slow self-discharge process (only 10-20% per year, of which 3-6% in the first month). The operating temperature range is 0 C - +65 C; at temperatures below zero, charging is impossible.

Charging occurs in several stages:

up to a certain point the maximum charging current flows;
when operating parameters are reached, the current gradually decreases to 3% of the maximum value.

During storage, periodic recharging is required approximately every 500 hours to compensate for self-discharge. When overcharging, lithium metal can be deposited, which, interacting with the electrolyte, forms oxygen. This increases the risk of depressurization due to increased internal pressure.

Frequent recharging greatly reduces battery life. In addition, the environment, temperature, current, etc. are affected.

The element has disadvantages, among which are the following:

terms of Use

It is best to store the battery under the following conditions: The charge should be at least 40%, and the temperature should not be very low or high. The best option is the range from 0C to +10C. Typically, about 4% of capacity is lost within 2 years, which is why it is not recommended to buy batteries from earlier production dates.

Scientists have invented a way to increase shelf life. An appropriate preservative is added to the electrolyte. However, such batteries should be “trained” in the form of 2-3 full discharge/charge cycles so that they can subsequently operate normally. Otherwise, a “memory effect” may occur and subsequent swelling of the entire structure. When used correctly and following all storage standards, the battery can last a long time, while its capacity will remain at a high level.

Since any battery (battery) is a source of constant electric current, sooner or later its charge will inevitably be depleted. With each recharge, its capacity will become less and less. These are the laws of physics.

You can only extend its work for a short time. Let's look at how to recondition a lithium-ion battery to gain the time needed to replace the battery.

IMPORTANT. If you are new to technology, then there is generally no need to read further - just go get a new battery or invite a competent friend. (No need to call godfather!).

In addition, you will learn about the causes of fire, explosion hazards, and aging of LIBs. This information will help determine what exactly happened to the battery, and will also make it possible to avoid operational errors.

So, lithium-ion batteries (LIBs) are used in a wide range of various modern technologies as a source of electricity. energy from mobile phones to storage devices in energy systems.

Their main performance indicators may vary within the following limits (this depends on their chemical composition):

Voltage (nominal) - 3.7 V or 3.8 V;
Maximum voltage - 4.23 V or 4.4 V;
Minimum voltage - 2.5–2.75 V or 3.0 V;
The number of charge-discharges is 600 (with a loss of 20% of capacity);
Internal resistance 5–15 mOhm/Ah;
Under normal conditions, the self-discharge value is 3% per month;
The operating temperature range is from minus 20°C to plus 60°C, the optimal temperature is plus 20°C.
If the voltage is exceeded when charging the LIB, it may catch fire. To protect against this, a controller is inserted into the housing. Its function is to disable the LIA. (Also controlling current, overheating and depth of discharge).
To reduce costs, not every lithium battery is equipped with a controller (or does not provide protection for all parameters).

INTERESTING: The first manufacturer of lithium batteries was Sony Corporation in 1991.

Design and advantages of LIB

A LIB consists of a cathode (on aluminum foil) and an anode (on copper foil), separated by an electrolytic separator and placed in a sealed “can.”

The cathode and anode are connected to the current collecting terminals.

The housing is sometimes equipped with a valve to relieve pressure in case of emergency operation.

In a lithium-ion battery (LIB), the charge is carried by a lithium ion. Its characteristic ability is the ability to penetrate into the crystal lattice of other materials (in our case, graphite, oxides or salts of metals), thereby forming chemical bonds.

Currently, three types of cathode materials are used:

Lithium cobaltates (thanks to cobalt, the number of charge-discharge cycles increases, and it also becomes possible to operate at low temperatures);
Lithium manganese;
Lithium ferrophosphate (low cost).
The advantages of LIBs are low self-discharge and a large number of cycles.

Disadvantages of LIA

The explosion hazard of Li-ion batteries in the first generation was justified by the occurrence of gaseous formations that led to a short circuit between the electrodes. This has now been eliminated by changing the anode material from lithium metal to graphite.

Explosion hazards also arose in cobalt oxide LIBs due to operational failures.

LIBs based on lithium ferrophosphate are completely free of this disadvantage.

IMPORTANT. Discharging LIBs at low temperatures (especially repeated discharge) leads to a reduction in return energy of up to tens of percent. In addition, LIBs “sharply” react to temperature when charging: the optimal temperature is +20 °C, and +5 °C is no longer recommended.

Memory effect

Research has confirmed the existence of a memory effect in LIB. But the point is its fundamental presence, and not its influence on the work as a whole.

The explanation for this process is as follows: the battery operates by periodically releasing and capturing lithium ions, and this process, when not fully charged, deteriorates due to disruption of the microstructure of the electrode.

IMPORTANT. Experts have identified two rules for extending the service life of LIBs:

Preventing complete discharge;
Do not charge near heat sources.

Aging

LIBs age even when not in use. Twenty percent of capacity is lost after just two years. You should not buy them “for the table”. When purchasing, look at the production date.

Low temperatures and power

Up to fifty percent of battery power is lost at operating temperatures below 0 °C.

Spontaneous combustion

LIBs are prone to spontaneous combustion. During thermal acceleration of a faulty (damaged) battery, substances are released that accelerate its self-heating (oxygen plus flammable gases). Therefore, it is capable of burning even in the absence of air.

To extinguish in such cases, provide for a lower temperature and prevent the spread of fire.

Let's start restoration

Once you already know from the above the “physics” and “chemistry” of the operation of the LIB and its filling, you can independently choose one of the methods for treating your battery, and also evaluate the “reasonableness” of the methods below.

Getting rid of gases

We already know that if used incorrectly, gaseous substances can form inside the “can.”

The essence of this method is that you need to get rid of them. To do this, first remove the upper block (controller), then pierce the discovered cap, and then press it against a hard surface with some kind of press to release gases.

After this, seal the hole with epoxy resin and return the controller to its place.

But before you revive your phone battery in this way, remember the expected dangers of this method:

Damage to the device due to excessive impact;
Damage to the electronics under the cap;
Possibility of explosion (spontaneous combustion) when the cathode is short-circuited with the anode.

Short-term “return” of capacity

You can briefly revive the battery if you “revive” it using a 5–12 Volt power supply, a resistor from 330 to 1000 Ohms and a power of at least 500 mW.

To do this, the contacts of the power supply are connected to the contacts of the LIB: minus to minus, and plus to plus through a resistor, the polarity of which is checked with a multimeter. Consumption time is no more than two to three minutes.

Please note that the parameters of the supplied current must correspond to the required ones, and use a voltmeter or tester to control the voltage.

We use the refrigerator

Following this simple method, battery restoration is carried out as follows:

The battery removed from the smartphone must be placed in the refrigerator for a period of twenty to thirty minutes, after placing it in a plastic bag. Then connect it to the charger for one minute, and then wait until it warms up to room temperature.

Allegedly, after these manipulations it can be used as usual.

Charge-discharge method

This method should be called a method of resuscitating a battery for a fifth-grade student.

According to the popularizers of this “joke,” the phone’s battery can be “brought to life” by charging it “several times” (the number of times is not specified) to a 100% charge and then completely discharging the battery. To discharge, it is advised to use some resource-intensive game or AnTuTu utility, each time removing and inserting it back into the mobile phone.

It remains unclear how the battery will be charged several times to 100 percent if it is already inoperative?

"Wild" recovery method

This “maneuver” consists in the fact that after removing the protective controller, you need to short-circuit the output current collector terminals with some metal object. After this, the controller returns to its place.

At the same time, another significant point is added - at the beginning of the procedure, for some reason, you need to peel off the sticker with the technical characteristics of the LIB. This is truly “dancing with a tambourine”!

Rocking the LIB disabled by the controller

To prevent deep discharge, lithium-ion batteries are equipped with a controller that puts them into a “shutdown” state. In this case, when measuring the voltage at its terminals in front of the controller, you can detect a value of about 2.5 volts. This means the battery is still alive!

To do this, the protection circuit is first turned off (unsoldered).

The “can” is connected to a universal charge-discharge device (for example, Turnigy Accucell 6). In this case, the device itself monitors the process and the restoration takes place under its control.

The “TYPE” button selects the “Li-Po” charging program, because our LIB is 3.7V.

By short pressing “START” the charging parameters are selected. For Li-ion - the value is 3.6 V, for Li-pol - 3.7 V.

You need to select “AUTO” for the parameter, since in our case the charging will not start due to the low battery charge.

The charge current must be set at ten percent of the battery capacity (in our case, 150 mA). The value is set using the “+” and “-” buttons.

When the battery charge reaches 4.2 V, the device will be switched to voltage stabilization mode, and upon completion of the process, a sound signal will sound and the message “FULL” will appear on the display.

And finally, a video about how you don’t need to recharge batteries

Safety Notes

Before reconditioning a lithium-ion battery, you should remember the following rules:

You should not leave a problematic LIB unattended during repairs. Spontaneous combustion is not a threat, but a real fact.
It is necessary to periodically monitor the temperature of the phone battery with a remote thermocouple, an electronic thermometer, or at least with your hand. If the surface appears hot rather than warm, repairs must be stopped immediately.
Do not use high currents for charging. The possible permissible maximum is 50 mA. This parameter is calculated by dividing the power supply voltage by the resistor capacitance. For example, at 12 V and 500 ohms it will be 24 mA.
Instead of a resistor, it is permissible to use a standard 80 mm computer fan.

Remember that the above methods do not give a 100% result, and in any case the responsibility lies with you. This is especially true for humanists.

Don't overestimate your knowledge and capabilities. It’s better to consult with knowledgeable people once again.

Share your experience with friends and write in the comments.

Greetings, my dear friends and admirers, readers of this blog. Instead of another lesson, it would be more correct to say articles in photo school piggy bank, I decided to write an article about a topic that is sore and important to everyone.

I think many, including you, my dear readers, will find it both interesting and useful to know what such fundamental things are lithium ion batteries, what are their limiting characteristics, how should they be used, what can be obtained with proper use, and of course, what should be the care for long battery life. So go ahead.

Why? - you ask me, I actually started writing on this topic. Well, a battery and a battery and what about it. So? But no. Li-ion battery, this is essentially a fuel tank for many of our favorite devices, or devices in common parlance. So what? - you tell me, - what difference does it make to us? And the difference is big and important for you. The idea to write this article came after the photography school students and I attended. The weather conditions are quite ordinary, about -7 -10 Celsius, sunny, light breeze, clear. Generally pleasant weather for the inquisitive eye of an amateur photographer. However, many students became worried: Isn’t this dangerous for the camera? Won't she freeze? What happens if it freezes? (I will write a separate note about the temperature conditions of the camera) What will happen to the camera battery? We heard that the camera battery is very sensitive to the cold and can fail, is this true? True, but not all and not entirely. Let's figure it out.

Our cameras contain lithium-ion batteries. What would that mean? Here's what. Li-ion batteries have significantly better usage parameters compared to other types of batteries. I won’t go into details, but nowadays, most manufacturers of consumer electronics are trying to equip their products with Li-ion batteries, since they are simpler and cheaper to produce and are less harmful to the environment.

Primary cells (“batteries”) with a lithium anode appeared in the early 70s of the 20th century and quickly found application due to their high specific energy and other advantages. Thus, a long-standing desire was realized to create a chemical current source with the most active reducing agent - an alkali metal, which made it possible to sharply increase both the operating voltage of the battery and its specific energy. While the development of primary cells with a lithium anode was crowned with relatively quick success and such elements firmly took their place as power sources for portable equipment, the creation of lithium batteries encountered fundamental difficulties, which took more than 20 years to overcome.

After many tests during the 1980s, it turned out that the problem with lithium batteries revolved around the lithium electrodes. More precisely, around the activity of lithium: the processes that occurred during operation ultimately led to a violent reaction, called “ventilation with flame emission.” In 1991, a large number of lithium batteries, which were first used as a power source for mobile phones, were recalled by manufacturers. The reason was that during a conversation, when the current consumption was at its maximum, a flame erupted from the battery, burning the face of the mobile phone user.

Due to the inherent instability of lithium metal, especially during charging, research has moved towards creating a battery without the use of Li, but using its ions. Although lithium-ion batteries provide slightly less energy density than lithium batteries, Li-ion batteries are safe when properly charged and discharged.

If further, someone is interested in the part about what chemical processes were and are in lithium-ion batteries, and how these same processes were tamed, then go to Google. I’m not strong enough in chemistry and physics to write an article that would make me fall asleep while reading it.

Modern Li-ion batteries have high specific characteristics: 100-180 Wh/kg and 250-400 Wh/l. Operating voltage: 3.5-3.7 V.

If just a few years ago, manufacturing developers considered the maximum achievable capacity of Li-ion batteries to be no more than several ampere-hours (remember the school physics course), now most of the reasons limiting the increase in capacity have been overcome and many manufacturers began to produce batteries with a capacity of hundreds of amperes -hours, or even thousands.

Modern small-sized batteries are operational at discharge currents of up to 2 C, powerful ones - up to 10-20 C. Operating temperature range: from -20 to +60 °C. However, many manufacturers have already developed batteries that operate at -40 °C. It is possible to expand the temperature range to higher temperatures.

The self-discharge of Li-ion batteries is 4-6% in the first month, then it is significantly less: in 12 months the batteries lose 10-20% of their stored capacity. The capacity loss of Li-ion batteries is several times less than that of nickel-cadmium (Ni-Cd) batteries, both at 20 °C and at 40 °C. Resource of lithium-ion batteries: 500-1000 charge-discharge cycles.

And here many will say: -Ahhh. This is why you can shoot with your camera in moderately cold temperatures. Yes, I will answer you. Plus, when the battery works, releasing energy, chemical reactions occur in it, the side effect of which is the release of thermal energy, which allows the battery to maintain its operating temperature range longer. In addition, when we take the camera out of the case on the street, it (the camera, the camera) also has a positive temperature, that is, we further increase the time resource during which we can shoot on the street at -7 ..-15 °C. Add to this the thermal heating of the camera processor during shooting, the heating of the matrix, even the warmth of the hands with which we hold the camera and transfer it to it, extends the thermal and time life of the camera at moderately low temperatures.

This concerns the use of batteries in work. Now let's look a little at the charge and storage side. Lithium-ion batteries do not require any special care. The basic rules for their operation can be found in the instructions for the phone/laptop/camera, and everything else is taken care of by the BMS circuit and the charge controller in the powered device. However, when buying, you can often hear the following statements from a seller or a fellow “guru”:

“...first charge - 12–15 hours...” or, alternatively, “...just leave the device connected all night...”;

“...you need to do 3-5 full cycles for the battery to gain capacity...”;

“...it is advisable to charge and discharge the battery completely...”;

“... so what if the battery is already a year old, it hasn’t been used; its service life depends solely on the number of charge-discharge cycles...”

Let's see how true the above is.

The first statement is simply meaningless - the control electronics will not allow the battery to be charged more than it should be.

Tip #2 is also untenable. After the first charge, lithium-ion batteries work with full efficiency, and at first they discharge faster simply because the owner of the device sets up and studies it, shows it to friends and acquaintances, etc. After a week or two, the gadget enters normal mode, which is natural , has a positive effect on autonomy. But one full charge before use is still advisable. This is not necessary for the battery, but so that the device can determine its real capacity and subsequently correctly display the remaining charge.

Recommendation No. 3 has “legs growing” even from the rules for operating nickel-cadmium batteries, which had to be completely discharged first, otherwise part of the capacity would be irreversibly lost. Their lithium-ion counterparts do not have a similar “memory effect”; moreover, deep discharge is contraindicated for them. With frequent use, this is not relevant, since the BMS system does not allow the battery to discharge completely, but if it remains in a discharged state for a month or more, the remaining charge will “leak away”, the protection circuit will block the charging process and turn off, after which charging will no longer be possible. Overcharging is also harmful, but most devices already take this into account and do not charge the battery to 100%.

There is also advice like “charge as you wish, but at least once a week (month) carry out a complete cycle.” This operating scheme is optimal for nickel-metal hydride batteries - they also have a memory effect, but much less than Ni-Cd, and restore capacity after 1-2 full cycles. For lithium-ion batteries this is only partially true; for example, it is recommended to do this after long-term storage.

From statement number 4, a seemingly logical conclusion follows: since the battery life is measured by the number of cycles, it means that it is better to use it to the maximum. This is a mistake. Full charge and discharge wear it out faster, while incomplete cycles, on the contrary, prolong life. In addition, lithium-ion batteries lose capacity even without use. Already after a year “on the shelf” their resource decreases by 5–10%, after 2 years – by 20–30%. Therefore, when purchasing a new portable device, pay attention to the release date of the power supply. It is also obvious that buying a battery for future use, even if it is difficult to find on sale, is useless.

It is very important to observe the operating temperature conditions of lithium-ion batteries. In frost below -20 °C they simply stop delivering current, and in heat above +45 °C although they function, such climatic conditions activate the aging process, significantly reducing the life of the battery. But you can charge it only at positive (Celsius) temperatures, otherwise there is a high risk of device failure. In general, the optimal operating temperature of lithium-ion batteries is +20 °C.

Lithium-ion batteries are constantly being improved, and manufacturers are actively experimenting with electrode and electrolyte materials. In 1994, batteries with lithium-manganese cathodes appeared, and in 1996 - with lithium-iron-phosphate cathodes. They are much more stable and can easily withstand high discharge currents, so they are used in power tools and electric vehicles. Since 2003, batteries have been produced that use a complex cathode composition (LiNiMnCoO2) and have the best combination of characteristics among all those listed. But no one has yet been able to surpass lithium-cobalt specimens in terms of specific capacity and price, and the advantages of the new types are not in demand in mobile phones and laptops that consume relatively little current.

If you have temporarily put your device aside, but want to keep its battery in working condition, know that lithium-ion batteries are best stored at a temperature of about +5 ° C. The higher it is and the closer the charge level is to 100%, the faster the battery ages and loses capacity. It is best to charge it to 40–50%, remove it from the device, pack it in a sealed plastic bag, put it in the refrigerator (but not in the freezer!) and recharge it periodically.

That's all I wanted to say about batteries, our friends, electronic pets. Be it a phone, a player or a camera.

This article was prepared based on materials found on the Internet and collected here in a pile for convenience and understanding of the essence of the process.

Any questions? Write in the comments and I will definitely answer.

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