CuCo₂O₄ nanosheet array as a multi-functional three-dimensional current-collector for high-performance lithium-sulfur batteries

Lithium-sulfur battery (LSB) is regarded as prospective secondary battery because of high specific capacity/energy density. However, the capacity attenuation resulted from slow reaction kinetics and severe “shuttle effect” during the cycle process seriously hinder its practical application. Herein, a carbon cloth supported CuCo₂O₄ nanosheet array (CCO@CC) was designed as a novel three-dimensional current-collector, adsorbent and electrocatalyst to restrain “shuttle effect” of lithium polysulfides (LiPSs). The combination of nanosheet array and bimetallic oxide increases the adsorption/catalytic sites of CCO@CC for lithium polysulfides and promotes ion/electron transfer, thus effectively accelerating redox reaction kinetic and inhibiting “shuttle effect” of LiPSs. The CCO@CC/AB@S-based cell exhibits high specific discharge capacities of 1296 mAh g⁻¹ (0.1C) and 567 mAh g⁻¹ (3C), and low decay per cycle of 0.037 % for 1500 cycles (1C). Even with high-sulfur loading of 5.4 mg cm⁻², the CCO@CC/AB@S-based cell still achieves high areal capacity of 5.47 mAh cm⁻² at 0.1C and a capacity retention rate of 81.5 % after 100 cycles at 0.5C, which provides a convenient and effective material design strategy for high-performance LSB.