Multishelled Ni2P Microspheres as Multifunctional Sulfur Host 3D-Printed Cathode Materials Ensuring High Areal Capacity of Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries have higher theoretical capacity and higher energy density, so they are considered to be one of the most promising candidates for next-generation energy storage devices. However, electrolyte-soluble polysulfides cause a shuttle effect and lead to poor cycle stability. This is one of the main obstacles to the practical applications of LSB technology. To overcome this problem, here, we report polar Ni2P hollow microspheres, with multilayer nesting, as sulfur host materials. Specifically, the multilayer polar Ni2P can simultaneously act as a multilayer physical barrier and chemical adsorption material. In addition, the Ni2P microspheres serve as activation catalysts, accelerating the redox reaction kinetics. The above features allow the structure to effectively suppress the shuttle effect and improve the discharge capacity and cycle stability of LSB. For example, the three-dimensional printed Ni2P@S (3DP-Ni2P@S) cathode can provide an initial capacity of 682 mAh/g, obtaining high cycle stability with low-capacity attenuation of 0.0072% per cycle for 400 cycles under 2C. Even when the sulfur loading is increased from 6.1 to 9.3 mg/cm(2), this material still shows good capacity retention. This work inspires the design of multifunctional cathode materials and paves a new path for the development of Li-S batteries.

Automated summary

This study presents multifunctional Ni2P hollow microspheres as sulfur host materials to overcome the shuttle effect caused by electrolyte-soluble polysulfides, enhancing the discharge capacity and cycle stability of lithium-sulfur batteries.