Living in an age that is totally handicapped with technology have its own perks. Technology has been everywhere in our life. The everyday revolution in various field brings more reliability and ease to our life. Lithium-ion batteries hold their own share in this surge of technology. Now when most of the industries are moving toward innovation, rechargeable lithium-ion batteries offer great help. The high energy density, cost-effective approach, high maintenance and effective charge/discharge cycle make lithium-ion batteries a more superior choice. Various big commercial industries, including automotive, portable devices industries and many other smartphone industries, have great demand for lithium batteries. Rechargeable lithium-ion batteries bring so much reliability in every sector, be it Electric Vehicles, Semi Hybrid Electric Vehicles or smartphones. The high density and low recharge cycle make it a practical choice for long time usage. The increased battery life services and common potential hazards bring much liking of customers for lithium-ion batteries. Various essential factors turned the demand for lithium batteries high compared to the other nickel and lead-acid batteries. This article summarizes all the vital facts, reasons and effects of lithium battery overcharge.
History of Rechargeable Lithium-ion Batteries
The concept of lithium-ion batteries has been developed and gain attention in 1970. As the starting, the idea holds essential and bare minimum qualities. With the few advancements and up-gradation, lithium-ion batteries instantly become commercial in the 1980s. At first lithium-ion batteries has struggled to perform the impactful function because it was made up of metal. With gradual advancement in the idea, a new concept was introduced in lithium batteries. Instead of metal, lithium ions chemistry utilized in the functioning of the lithium-ion batteries. The first attempt at rechargeable lithium batteries production has been a trend to improve its working and efficiency. Constant improvement in the functioning and capabilities of lithium-ion batteries bring so many potential benefits to the various big electrical devices corporations. Li-ion batteries gain more attention from people around the world due to their high energy and power density. Lower self-discharge and long cycling provide more reliability to lithium batteries. Lithium batteries are made up of tiny cells requiring smart electronics to ensure their maximum operating quality.
Lithium-ion Batteries Charging Process
One of the most prominent features of lithium batteries is their reasonable charge and discharge cycle. Usually, lithium batteries are rechargeable which significantly an essential benefit is for big automotive companies. A new lithium battery delivered from the company holds an average charging of 30%. This value is the average, but mostly it depends on the manufacturer and mAh of the battery. People might get confused that why not fully charged them before delivering? The answer is quite simple because of the safety issues. Like other electronic batteries, lithium batteries also hold a specific discharge rate. The typical discharge rate of each cell of lithium battery is about 1-5% per year. But this figure can be changed depending on the temperature and other factors. Mostly charging a new battery at 100% would cause a high in its voltage.
The nominal voltage of a lithium battery is about 3.4V. Other than that, there are also two types of voltage for rechargeable lithium batteries. One is fully charged voltage which is about 4.2V. The full discharged battery hold a voltage of about 3.2V. An imbalance in this figure might cause potential hazards. For example, if the battery voltage will reach to 4.2V and you still charge the lithium battery, then there is a high chance of explosion or firework. Similarly, when the discharge voltage gets too low, and you still do not charge your lithium battery, there are high internal short chances. So having a balance in the charging process of lithium battery is very crucial for its proper functioning.
What is Lithium Battery Overcharge?
Using our mobile phone chargers and batteries, we all might well aware of the overcharging process. In lithium battery overcharge, it is a process when the battery will be charged above the specified voltage. Along with the batteries, overcharging is harmful to the safety of users too. There are various factors involved in the overcharging of your battery. Some might be related to your carelessness, while others could be technical. For example, a quality charger could prevent the lithium batteries from overcharging. The charger of your battery must be matched with the output voltage and mAh rating of your battery. It’s easier to avoid overcharging in lithium-ion batteries because they can receive a partial charge or be charged intermittently.
The critical feature of lithium battery is that they are rechargeable, and you can use them by charging once in a reasonable period. In comparison to lithium batteries, lead-acid batteries have a complex charging system and must be charged fully once plugged in. That feature of lead-acid batteries could make them more prone to be overcharged. But lithium batteries do not hold any such credential. During lithium battery overcharge, the voltage has prime importance. Because if not handle with precision, it might cause a recipe for firework. 4.2V is the average voltage value for a charged battery. This voltage could be achieved at 50-60 percent.
Overcharge Process of Lithium Batteries
The overcharging process of the lithium batteries is an electromechanical thermal couple’s process. The ohmic heat generation, gas generation, and other series of exothermic reactions are linked with the overcharging process of lithium batteries. At the start of overcharging process, significant ohmic heat will be generated. The anode becomes fully lithiated, which result in the deposition of lithium metal on the surface of that anode. Continue charging will cause a temperature rise. The electrolytes in the lithium-ion batteries will react with the deposited lithium at that elevated temperature. On the other hand, due to overcharging lithium batteries, cathode could bear permanent structural change by the dissolution of transitional metals.
The electrolytes oxidized on the cathode during the overcharging process. This might be because of the potential exceed of voltage from a specified safety voltage. Physically, overcharging can also be observed because of the swear batter swelling because of the undergoing processes. This is particularly harmful because the battery could explode at any time when the internal pressure exceeds the set limits. Battery deformation, an internal short circuit could also be resulted in overcharging lithium-ion batteries. Battery rupture resulting from overcharging could expose the cathode and anode to the air and moisture in the air. This will cause many exothermic reactions, which causes combustion of flammable gas and fierce heat release.
Effect of Lithium Battery Overcharging
Overcharging could ultimately damage the functional efficacy and working capacity of a lithium-ion battery. In most cases, people lose their lithium batteries because of overcharging or discharging process. These batteries already offer minimal and low recharge cycle, and handling them with precision could lead to a long battery service life. Overcharging could bring potential harm to the batter and hazardous for the user’s safety. Inside the lithium battery, overcharging can create unstable conditions by increasing the pressure and causing a thermal runaway. Physical shape change, loss of working capability, and battery rupture are also linked with the overcharging of lithium battery above the set voltage of a fully charged battery.
Rechargeable Lithium Battery Overcharge Protection
When you see the rapid market size growth of lithium batteries, it’s not just because of its cost or other functional reliabilities. There are more of it. The most remarkable feature about lithium-ion batteries is their supervisory system. This actually helps in monitoring the overcharge for the battery cells. This specific protection circuit actually cut off the flow of excessive lithium ions that move across the cathode and anode. By that process, it could protect the battery from excessive pressure build-up. The temperature could also be retained by that process. Other than the protection circuit, one more unique feature of lithium-ion batteries is their compatible and effective battery management system. BMS of the lithium batteries monitor the state of charge; it cut off the current when the limit of charged voltage reached. Although this feature is pretty handy, the user still needs to be more practical and attentive about the charging of the lithium battery. You can avoid the complex process of dealing with the overcharging or discharging of the lithium batteries by being regular during charging.
Process of Lithium Battery Charging
Lithium batteries use a different charging process compared to other nickel-cadmium and lead-acid batteries. It utilizes a constant-current and constant-voltage method of charging during the first stage of its charging cycle. The first stage is the peak voltage stage, and after completing this stage, charging enters the saturation charge stage. The whole process takes a maximum of 1-2 hours in total. You can use your lithium battery until it holds about 20% of the capacity. It’s easy to charge your battery, just plug in during your short launch break and top up your battery without getting it too low. Many manufacturers design lithium-ion battery packs with chargers integrated within the pack that can be plugged into regular electrical outlets. It means that you even don’t need to position your battery near the installed wall to charge them.