Battery Self Discharge In Lithium-ion Batteries
For rechargeable batteries, battery self discharge is a normal phenomenon. The self discharge of rechargeable batteries does not pose a significant threat to the battery’s lifespan.
However, some factors can increase the self discharge rate. The main purpose of this article is to help you fully understand battery self discharge.
What Is Battery Self Discharge?
It refers to the loss of some capacity of a battery with a certain amount of charge after being stored at a certain temperature for a period of time.
Battery self discharge is a chemical reaction that occurs inside a battery.
Even if the battery is not connected to an external circuit or between battery electrodes, it will discharge the battery.
How Does Self Discharge Occur In Lithium-Ion Batteries?
The main reason for self discharge of lithium-ion batteries is that their electrolytes contain organic compounds.
Regardless of whether the battery is in the charging process, organic electrolytes will decompose over time.
As the organic electrolyte decomposes (through internal chemical reactions), the battery’s charge decreases, leading to self discharge.
The three main factors affecting the self discharge of lithium batteries
● Extremely high temperature
High temperatures are not friendly to lithium batteries because they can promote self discharge and shorten their lifespan.
High temperature will intensify the reaction between the negative electrode and the electrode, consequently increasing the self discharge rate of the battery.
Additionally, it will also have a negative impact on the SEI layer of lithium-ion batteries. Heat can cause degradation and rupture of the SEI layer in lithium-ion batteries.
● Moisture content
Storing lithium-ion batteries in damp rooms is very dangerous because moisture can damage the battery.
The dissolution of water in the electrolyte can cause electrolytic imbalance, resulting in electrical short circuits in lithium-ion batteries.
Therefore electric short circuit can cause self discharge of lithium-ion batteries.
● Micro short circuit
Micro short circuits can cause a small amount of current to leak inside the battery, thus leading to self discharge of the lithium battery.
How To Extend The Lifespan Of Lithium Batteries?
- Use the recommended lithium battery charger.
- Have a clear understanding of the performance specifications of your lithium-ion battery.
- Store the battery in a cool, dry place, away from other metal components.
- Do not overcharge or discharge excessively.