Abstract:

In the process of LIB production, the formation processes aim at achieving the wetting of the electrodes and the activation of the electrode materials. Meanwhile, during the initial charge, with the insertion of lithium ions, the electrolyte components are reduced in the anode and form a stable solid electrolyte interface film on the anode for preventing the irreversible consumption of the electrolyte and lithium ions in the subsequent cycling. Consequently, these techniques are of great significance for the battery performance; the formation effect directly affects the subsequent performance of LIBs, including storage performance, cycle life, rate performance and safety. However, for each single battery in the battery pack of electric vehicles, it takes days or even weeks to carry out the formation and conditioning processing, resulting in low battery production efficiency. A large amount of charge/discharge equipment, temperature control equipment, and environmental space increases the cost of battery production. The traditional formation method cannot completely meet the requirements of high performance, such as capacity, life, and safety, in LIBs. To date, there have been many studies on improving the battery performance and reducing the formation time and the cost of battery production by optimizing the formation technique of LIBs. This review focuses on the optimization of the lithium-ion formation technique, introducing the significance of battery formation, cost analysis, and various technological parameters and forecasting the future research and improvement directions.

Key words: lithium ion batteries, formation technique, SEI films, production efficiency, cost of production