Self discharge lithium ion battery

Why do lithium ion batteries self-discharge?

To find the cause of self-discharge, scientists need to identify the complex chemical mechanisms that trigger the degradation process in the battery. Lithium-ion batteries are rechargeable and use lithium ions to store energy. The cathode and the electrolyte are two key components in lithium-ion batteries.

Are all batteries affected by self-discharge?

All batteries are affected by self-discharge. Self-discharge is not a manufacturing defect but a battery characteristic; although poor fabrication practices and improper handling can increase the problem. Self-discharge is permanent and cannot be reversed. Figure 1 illustrates self-discharge in the form of leaking fluid.

How much electrical self-discharge does a battery have?

The amount of electrical self-discharge varies with battery type and chemistry. Primary cells such as lithium-metal and alkaline retain the stored energy best, and can be kept in storage for several years. Among rechargeable batteries, lead acid has one of the lowest self-discharge rates and loses only about 5 percent per month.

What is battery self-discharge?

Battery self-discharge is caused by the internal reactions in a battery that reduce the energy stored without any connection with an external circuit. In other words, the battery loses the energy stored in it by itself due to its internal behaviour even when the connected application is not demanding any energy.

Why do batteries self-discharge?

Charging the battery reverses the flow of the charged ions and returns them to the anode. Previously, scientists thought batteries self-discharge because not all lithium ions return to the anode when charging, reducing the number of charged ions available to form the current and provide power.

How often does a lithium ion battery self-discharge?

Regular full discharge cycles keeps memory under control (See BU-807: How to restore Nickel-based Batteries) Li-ion self-discharges about 5 percent in the first 24 hours and then loses 1–2 percent per month; the protection circuit adds another 3 percent per month.