Very long cycling of lithium ion batteries with lithium rich cathode materials

Abstract

Lithium ion batteries can be activated and then cycled to exploit a moderate fraction of the discharge cycling capacity such that the discharge capacity and average discharge voltage stay within initial values for thousands of cycles. The superior cycling performance has been achieved at relatively high discharge rates and for practical battery formats. Lithium ion battery performance can also be achieved with superior cycling performance with partially activated batteries such that good discharge capacities can be exploited for many thousands of cycles before the discharge capacity and average discharge voltage drops more than 20% from initial values. The positive electrode active material can be a lithium rich metal oxide. The activation of the battery can comprise phase changes of the active materials. As described herein, the phase changes can be manipulated to exploit a reasonable fraction of the available high capacity of the material while providing outstanding cycling stability.