Aqueous lithium-ion battery of Li4Ti5O12/LiMn2O4 using a lithium-ion conductive solid electrolytes separator

This study investigated the electrochemical properties and performance of an aqueous lithium-ion battery of Li4Ti5O12/LiMn2O4 (LTO/LMO) using a lithium-ion conductive solid electrolyte (SE) composed of NASICON-type Li-Al-Ti-P-O glass ceramic as a separator and a high concentration LiCl-based aqueous electrolyte in order to enhance charge-discharge and cycle life performance. The evolution of H-2 gas at the LTO anode during charging was found to be kinetically suppressed by using the SE separator and Zn coating on the LTO anode. As a result, the amount of H-2 gas was less than 2.6% that of the porous separator. The SE separator enabled the aqueous electrolyte on the LMO cathode and LTO anode sides to maintain an acidic and a basic solution, respectively, which widened the electrochemical window. Aqueous LTO/LMO batteries using the SE separator exhibited an average voltage of 2.4 V and a high anode capacity of 170 mAh g(-1) during charge-discharge cycling test at a rate of 1 C between 2.1 and 2.6 V. It was demonstrated that the battery using a Li2SO4-based aqueous electrolyte in the LMO cathode had good cycle performance and maintained a high coulombic efficiency of 99% after 100cycles.

Automated summary

This study investigated the electrochemical properties and performance of an aqueous lithium-ion battery using a lithium-ion conductive solid electrolyte as a separator and a high concentration LiCl-based aqueous electrolyte to enhance charge-discharge and cycle life performance. The SE separator effectively suppressed the generation of H-2 gas, leading to improved battery performance. Aqueous LTO/LMO batteries using the SE separator exhibited high charge-discharge efficiency, large capacity, and maintained good cycle performance even after 100 cycles.