Solid State Ionics, Vol.140, No.1-2, 83-87, 2001
Solid state lithium secondary batteries using an amorphous solid electrolyte in the system (100-x)(0.6Li(2)S center dot 0.4SiS(2)) center dot xLi(4)SiO(4) obtained by mechanochemical synthesis
Electrochemical cells were constructed using amorphous materials in the system (100 - x)(0.6Li(2)S .0.4SiS(2)). xLi(4)SiO(4), obtained by mechanochemical synthesis, as an electrolyte, LiCoO2 as a positive electrode and indium as a negative electrode. Charge and discharge behaviors of the cells at a constant current were investigated to see the possibility for utilization as secondary batteries. Charge-discharge efficiency at the Ist cycle was more than 75% in the cells using the solid electrolytes synthesized by mechanical milling (MM) for more than 5 h. Charge-discharge curves of the cells using the amorphous materials milled fur more than 10 h, were similar to those of the cells using the corresponding melt-quenched glass samples. The charge-discharge capacity decreased gradually from 90 to 70 mA h/g till about the 10th cycle, and became stable after the 10th cycle. The Coulombic efficiency of the cell showed almost 100%, except for the Ist and 2nd cycles. The amorphous materials synthesized by MM were concluded to work as the electrolyte for solid state lithium secondary batteries,
Keywords:solid state lithium secondary battery;mechanochemical synthesis;solid electrolyte;amorphous material;oxysulfide