NiS Nanorods as Cathode Materials for All‐Solid‐State Lithium Batteries with Excellent Rate Capability and Cycling Stability

Abstract

AbstractRate capability and cycling stability are the great challenges of all‐solid‐state lithium batteries, owing to the low lithium ion transfer kinetics in solid materials and poor interfacial compatibility between electrodes and electrolytes. In this work, one‐dimensional nanostructured NiS and lithium metal are firstly employed in Li/70 % Li2S–29 % P2O5–1 % P2O5/Li10GeP2S12/NiS all‐solid‐state lithium batteries, exhibiting excellent rate capability and cycling stability. NiS nanorods, with a diameter of 20–50 nm and length of 2–3 μm, are prepared in a controllable manner by using a solvothermal method. Electrochemical performance measurements show that the reversible discharge capacities of NiS nanorod electrodes can be as high as 670, 401, and 299 mAh g−1 at the current densities of 100, 250, and 500 mA g−1, respectively. Also, it displays excellent cycling stability, showing reversible discharge capacities up to 338 and 243 mAh g−1 after 100 cycles at current densities of 250 and 500 mA g−1, respectively. The electrochemical reaction mechanism of the NiS nanorods in all‐solid‐state lithium batteries is revealed by combining cyclic voltammetry and ex situ XRD measurements in detail, showing a reversible conversion reaction that is almost identical with that in the traditional lithium‐ion batteries that utilize liquid electrolytes.