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

Rate 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 mu m, are prepared in a controllable manner by using a solvothermal method. Electrochemical performance measurements show that the reversible discharge ca-pacities of NiS nanorod electrodes can be as high as 670, 401, and 299 mAhg(-1) at the current densities of 100, 250, and 500 mAg(-1), respectively. Also, it displays excellent cycling stability, showing reversible discharge capacities up to 338 and 243 mAhg(-1) after 100 cycles at current densities of 250 and 500 mAg(-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.