Impact of Li2O/metal mole ratio on lithium-ion battery anode performance

Abstract

In this study the electrochemical impact of Li2O/metal mole ratio on the cycle life of lithium-ion battery anode materials is demonstrated. For this purpose, nanostructured layered LiNi1/3Mn1/3Co1/3O2 (LiNMC) and spinel LiMn1.5Ni0.5O4 (LiMNO) materials, traditionally known as cathode materials, are evaluated as anode materials and compared against their lithium-free versions NMC (Ni:Mn:Co=1:1:1) and MNO (Mn:Ni=3:1). The Li2O/metal ratio in fully lithiated states are 2.0 for lithium containing (LiNMC and LiMNO) and 1.3 for lithium-free (NMC and MNO) samples. Battery tests show that capacity fading of lithium containing samples is 3 to 4 times larger than lithium-free samples. The differences in the electronic conductivities and voltages profiles of lithium containing and lithium-free anode materials are suggested to be the origin of such electrochemical disparity.