Effect of sol composition on solid electrode/solid electrolyte interface for all-solid-state lithium ion battery

A property of interface between solid electrode and solid electrolyte is one of the most important keys to fabricate all-solid-state lithium ion battery. In this study, an influence of sol composition used for preparation of the electrode on the property of interface between electrode and electrolyte was examined. LiMn 2O 4/honeycomb Li 0.55La 0.35TiO 3 (LLT) and Li 4Mn 5O 12/honeycomb LLT half cells were fabricated by impregnation of mixture of active materials with various precursor sols into honeycomb holes. In the case of LiMn 2O 4 cathode, the sol composed of nitrate salt provides large contact area of LiMn 2O 4 and LLT, resulting in higher performance of the cell. Li 2MnO 3 impurity was produced at Li 4Mn 5O 12/LLT interface prepared by the precursor sol composed of only nitrate or acetate salts although no impurity phase was observed at the interface prepared by acetate–nitrate sol containing lithium acetate and manganese nitrate. Li 4Mn 5O 12/honeycomb LLT half cell prepared by the acetate–nitrate sol showed the best performance among them. It is concluded that composition of the precursor sol strongly influenced on the interface of electrode and electrolyte. The all-solid-state Li ion battery composed of LiMn 2O 4/honeycomb LLT/Li 4Mn 5O 12 was successfully operated and the discharge capacity was 32 μAh cm −2.