A comprehensive review of pre-treatment discharge of the spent lithium-ion cells

Nowadays, the surge in the retirement of spent lithium-ion cells (SLICs) highlights the urgency of their recycling efforts with reusing valuable metals and environment protection. Significantly, there hides a risk of fire if SLICs containing residual energy are disassembled and separated directly without pre-treatment discharge. As such, pre-treatment discharge is an essential precondition for recycling and making use of SLICs. Consequently, physical and chemical discharge methods proposed by researchers have been reviewed and compared commonly in this article. Especially, chemical discharge solutions are classified and discussed based on their composition and action mechanism. The importance of pre-treatment discharge and future development direction are emphasized with an innovative sight on analyzing the distinguishing features and effectiveness of various methods. Eventually, the selection principles of discharge pre-treatment methods are also suggested from the perspective of enterprise implementation.