Effect of Mass Balancing on Cell Performance and Electrochemical Investigation of Sn–Ni Alloy as Anode for Li-Ion Capacitors

Abstract

Lithium-ion capacitors (LICs) have been attracting research interest over the past years as promising electrochemical energy devices because they show higher energy densities than supercapacitors and higher power densities than batteries. In this study, we synthesized an Sn–Ni alloy by electrodeposition and applied it as an anode for LICs. To optimize the full-cell configuration, we controlled the mass balancing between the loading amounts of active materials in the cathode and anode with different mass ratios of 16:1, 8:1, and 4:1. In addition, the Sn–Ni alloy was investigated using electrochemical impedance spectroscopy under different depth of discharge (DOD) levels. The LICs assembled with a mass ratio of 4:1 between the cathode and anode exhibited good cyclability, rate performance, energy, and power density. This study not only improved the cycle performance of LICs full cell by mass balancing, but also revealed the relationship between the electrochemical characteristics of LICs and DOD levels of the Sn–Ni anode.