Self-discharge can significantly limit the shelf life of batteries. The rate of self-discharge can be influenced by the ambient temperature, state of charge of the battery, battery construction, charging current, and other factors. Primary batteries tend to have lower self-discharge rates compared with rechargeable chemistries.
Upon scrutinizing the self-discharge mechanisms and mitigation strategies for both rechargeable batteries and high-power devices, peripheral similarities emerge in their self-discharge mechanisms. Consequently, comparable strategies can be devised to curb self-discharge.
Similarities between battery chemistries and causes of self-discharge are identified; concepts and ideas obtained this way are outlined. As an outcome of a better understanding of both common and system-independent causes and mechanisms of self-discharge as well as chemistry-specific processes approaches to reduce self-discharge are presented.
So far, the self-discharge in LIBs is comparatively the most studied device up to the pouch cell level. However, in contrast, the self-discharge studies in other rechargeable batteries are in an immature state, and more investigations are required.
The main factors that cause the self-discharge in rechargeable batteries include internal electron leakage due to electrolyte partial electronic conductivity, external electron leakage from poor battery sealing, electrolyte leakage, electrode mechanical isolation from the current collector, etc.
Moisture causes an electrolytic imbalance in the battery resulting in higher self-discharge rates. In addition to electrolyte breakdown, the formation of micro-cracks in the separator contributes to self-discharge in Li-ion batteries.
We have studied the variation of capacity, direct current resistance (DCR), open-circuit voltage (OCV), and self-discharge rate (k OCV) in the initial and aged states, and analyzed the sequence of their variation effects on the cycle life of …