Ethylene glycol pillared nickel hydroxide with efficient lithium storage capability

Abstract

Nickel hydroxide has emerged as a promising anode material for lithium-ion batteries (LIBs) on account of its large theoretical capacity and easy preparation. Unfortunately, the poor cyclability severely impedes its practical applications. To improve the cycling performance of nickel hydroxide, herein, we synthesize ethylene glycol (EG) pillared nickel hydroxide (EG-NH) through a hydrothermal method. By pre-inserting EG molecules, the interlayer distance of nickel hydroxide is expanded from 4.60 to 18.28 Å. Benefitting from the much-expanded interlayer distance, the EG-NH sample exhibits much-improved cycling performance, rate capability, and electrochemical reaction kinetics as compared to the bare nickel hydroxide (NH). At the current density of 500 mA g−1, the EG-NH sample maintains a high capacity of 876 mA h g−1 after 500 cycles, much larger than the NH sample (only 385 mA h g−1). In addition, the EG-NH sample exhibits smaller electrochemical reaction resistance and a higher Li+ diffusion coefficient than the NH counterpart. The present work offers a facile and efficient strategy for optimizing the lithium storage performance of nickel hydroxide by pre-inserting organic molecules in the interlayer space.