AUTHOR=Fan Jinchen , Zheng Yujun , Zhao Zhongshu , Guo Wenyao , Zhu Sheng TITLE=Nitrogen, Phosphorus, and Sulfur Tri-doped Carbon A Coated NiCo2Se4 Needle Arrays Grown on Carbon Cloth as Binder-free Anode for Potassium-Ion Batteries JOURNAL=Frontiers in Materials VOLUME=9 YEAR=2022 URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2022.875684 DOI=10.3389/fmats.2022.875684 ISSN=2296-8016 ABSTRACT=

Bimetallic selenides are considered to be the promising high-capacity anode materials for potassium ion batteries (PIBs). However, the dramatic volume fluctuation of K⁺ ions and pulverization during cycling still limit their practical application in PIBs. Herein, the nitrogen, phosphorus, and sulfur tri-doped carbon (SPNC)-coated bimetallic NiCo₂Se₄ needle arrays grown on carbon cloth (NiCo₂Se₄⊂SPNC/CC) prepared as a binder-free anode for PIBs. The polyphosphazene (PSZ) was used as ingenious heteroatoms doping carbon source. The coated SPNC layer derived from the PSZ on the surfaces of NiCo₂Se₄ needle arrays not only effectively alleviate the volume expansion of NiCo₂Se₄ but also provide abundant active sites for the storage of K⁺ ions. As the PIB anode, the NiCo₂Se₄⊂SPNC/CC could deliver a high reversible capacity of 880.9 mA h g⁻¹ at a current density of 0.1 A g⁻¹. After 500 cycles, the NiCo₂Se₄⊂SPNC/CC anode still maintains a high reversible capacity of 268.1 mA h·g⁻¹ at a current density of 0.5 A g⁻¹.