Bulk-Type Solid-State LIB

Abstract

The all-solid-state batteries have the potential advantages of safety performance for an accident such as thermal shock during utilization. In this chapter, we introduce some studies using the bulk-type solid-state test cells as examples for the investigation of electrode materials and electrode composites. LiAlO₂ coating on LiNi_1/3Mn_1/3Co_1/3O₂ (NMC) was investigated in order to improve the electrochemical properties of the all-solid-state battery using a sulfide-based solid electrolyte amorphous Li₃PS₄. The LiAlO₂ coating on NMC powders was carried out by the use of a sol–gel method. A bulk-type solid-state test cell was constructed with the obtained LiAlO₂-coated NMC. The charge–discharge cycling test of the cell revealed that the test cell with LiAlO₂-coated NMC showed the capacity larger than 124 mAhg⁻¹ even after 400 cycles. Incidentally, the amount of solid electrolyte in the composite electrode limits the total energy density of the battery. In order to reduce the solid electrolyte content in the positive electrode composites, we were conducted on the solid electrolyte coating on the active materials NMC by a wet process. The test cell with the Li₃PS₄-coated NMC showed the capacity of 145mAhg⁻¹, which was calculated on the base of the NMC weight in the composite electrode. The capacity was larger than that of the non-coated NMC. The all-solid-state battery with the Li₃PS₄-coated NMC had larger specific energy density than that with the non-coated NMC with the same Li₃PS₄ content.