Tape casting manufacturing of thick Li4Ti5O12 ceramic electrodes with high areal capacity for lithium-ion batteries

Abstract

In this work we report the preparation of additive-free ceramic Li4Ti5O12(LTO) electrodes with high thickness(∼250mum) by the conventional tape casting method followed by binder removal and sintering. By optimizingthe sintering process, high porosity (25-35 %), needed for a good electrolyte wetting, was achieved. In addition,the use of an Ar/H2reducing atmosphere during the thermal treatments increases the required electronic conductivity of the sintered electrode due to the combination of a carbon coating coming from incomplete binder decomposition and the partially reduction of Ti4+. Due to the absence of binders, the final electrode has almost 100 wt. % active material, leading to very high volumetric (250 mA h cm-3) and areal (6-8 mA h cm-2) capacities. This process paves the way for large-scale production of thick electrodes with applications in all-solid-state batteries (ASSBs), leading to more safety lithium-ion batteries (LIBs).