Hybrid and aqueous Li+-Ni metal batteries

Abstract

Aqueous metal batteries have attracted particular attention due to their low cost, environmental friendliness, and high safety. However, they still face challenges that hinder practical applications, including the oxygen and hydrogen evolution and formation of the dendrite. Herein, we propose a novel hybrid-ion battery with Ni metal as the anode. Due to the electrostatic shielding effect of Li+, the surface of deposited Ni is smooth and dendrite-free, which enables an ultralong lifespan of over 4000 h and high coulombic efficiency over 99.5%. When coupled with spinel LiMn2O4 cathode, Li+ is the dominant charge carrier undergoing deintercalation and intercalation at the LiMn2O4 cathode, whereas Ni2+ is stripped from or deposited on the Ni anode. The proposed hybrid cell achieves high-capacity retention of 81% after 1000 cycles at 500 mA g−1, a superior rate performance with a specific capacity of 64 mAh g−1 at 2000 mA g−1, and good temperature tolerance. In addition, the hybrid pouch cell shows excellent electrochemical performances that further demonstrate its great potential as a new energy storage system.