Ab initio calculations of Li2(Co, Mn)O8 solid solutions for rechargeable batteries

Abstract

Current commercially available rechargeable Li-ion batteries, for example LiCoO2, are working mostly in the 4 V regime. One often suggested possibility to improve the effectivity of Li-ion batteries are the creation of the 5 V cathode materials. We performed quantum mechanical calculations on the average battery voltage for the Li2CoxMn4−xO8 (x = 0, 1, 2, 3 and 4) cathode materials by means of the WIEN2k computer program package. The calculated average battery voltages for x = 0, 1, 2, 3 and 4 are equal to 3.95, 5, 4.47, 4.19 and 3.99 V. Our ab initio calculation results are compared with the available experimental data for x = 0, 1, 2 and 4 which are equal to 4, 5, 5 and 4 V. Thereby, for the Li2Co1Mn3O8 battery cathode material, our calculated average battery voltage around 5 V is in perfect agreement with the experimentally available battery voltage value of 5 Volt. Nevertheless, our calculated average battery voltage is underestimated (4.47 V) for the Li2Co2Mn2O8 cathode material, which also experimentally exhibits the 5 V voltage.