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

Graphical Battery all stars : 1D nanostructured NiS is demonstrated to be a promising active material for all-solid-state lithium batteries. Lithium metal, rather than the Li–In alloy, is employed as the anode of batteries to improve the energy density. The obtained all-solid-state lithium batteries exhibit excellent rate capability and cycling stability, with discharge specific capacities of 338 and 243 mAh g −1 after 100 cycles at current densities of 250 and 500 mA g −1 , respectively. 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 % Li 2 S–29 % P 2 O 5 –1 % P 2 O 5 /Li 10 GeP 2 S 12 /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.