Enhancing NMC/silicon alloy full cell cycling by adding water to the electrolyte

Abstract

Water was intentionally added to full Li-ion cells with silicon alloy/graphite negative electrodes and was found to improve cycling when LiNi0.3Mn0.3Co0.3O2 was used as the cathode, but negative impacts when LiCoO2 was the cathode. LiNi0.3Mn0.3Co0.3O2 versus Si-alloy/graphite full cells with 1000 ppm water additive exhibited a 17% enhancement in capacity retention. The enhancement to cycle life was similar to using 10% FEC additive. From these results, we believe that water could be a potentially low-cost additive for use in Li-ion cells with LiNi0.3Mn0.3Co0.3O2 and Si-alloy containing negative electrodes.