DEEP-DISCHARGE CONDITIONING FOR LITHIUM-ION CELLS

摘要

A process of reconditioning a lithium-ion cell is provided that unexpectedly improves cell capacity, reduces cold temperature impedance and increases cold cranking amps. The process involves a reconditioning step of holding a cell at a sub-discharge voltage for a recovery time. The sub-discharge voltage is 1.0V or less in many embodiments, optionally 0.0V. Holding this sub-discharge voltage for a recovery time of several hours will result in recovery of lost capacity that is in excess of that explainable by recovery of ions transferred to an anode overhang.

主权项

1. A process for reconditioning an electrochemical cell comprising:
cycling a lithium-ion cell to an operational discharge voltage 50 or more times; cycling the lithium-ion cell to a sub-discharge voltage of less than 2.0 Volts; holding the lithium-ion cell at the sub-discharge voltage for a recovery time sufficient to increase capacity of the lithium-ion cell.