Petal-like Mn-doped α-Ni(OH)2 nanosheets for high-performance Li-S cathode material.

ABSTRACT

Lithium-sulphur (Li-S) batteries are high-energy-density and cost-effective batteries. Herein, petal-like Ni1-x Mn x (OH)2 (x ≈ 0.04) nanosheets were synthesised using a hydrothermal method and the electrical conductivity of Ni(OH)2 was improved by applying the cathode functional materials in Li-S batteries. With up to 5 mg cm-2 of S content in the cathode, the fabricated Ni1-x Mn x (OH)2 electrode exhibited specific discharge capacities up to 1375 and 1150 mA h g-1 at 0.2 and 0.5C, and retained this capacity at 813 and 714 mA h g-1 after 200 cycles, respectively. Electrochemical measurement results show that Ni1-x Mn x (OH)2 plays a critical role in Li-S batteries as it has a larger specific surface area than Ni(OH)2, which has superior adsorption performance toward lithium polysulphides. Moreover, the conductivity performance of Ni1-x Mn x (OH)2 is significantly better than that of Ni(OH)2, which improves the electrochemical reaction kinetics of the Li-S batteries.