Boron-Doped Pine-Cone Carbon With 3D Interconnected Porosity for Use as an Anode for Potassium-Ion Batteries With Long Life Cycle

Jian-Fang Lu; Ke-Chun Li; Xiao-Yan Lv; Hong-Xiang Kuai; Jing Su; Yan-Xuan Wen

doi:10.3389/fchem.2022.953782

Boron-Doped Pine-Cone Carbon With 3D Interconnected Porosity for Use as an Anode for Potassium-Ion Batteries With Long Life Cycle

Front Chem. 2022 Jul 6:10:953782. doi: 10.3389/fchem.2022.953782. eCollection 2022.

Authors

Jian-Fang Lu^{1

2}, Ke-Chun Li³, Xiao-Yan Lv⁴, Hong-Xiang Kuai¹, Jing Su¹, Yan-Xuan Wen^{1

5}

Affiliations

¹ School of Chemistry and Chemical Engineering, Guangxi University, Nanning, China.
² School of Chemistry and Chemical Engineering, Guangxi Minzu University, Nanning, China.
³ School of Materials and Environment, Guangxi Minzu University, Nanning, China.
⁴ The New Rural Development Research Institute, Guangxi University, Nanning, China.
⁵ Guangxi Key Laboratory of Processing for Non-ferrous Metallic and Featured Materials, Guangxi University, Nanning, China.

Abstract

Potassium-ion batteries (KIBs) have received widespread attention as an alternative to lithium-ion batteries because of their low cost and abundance of potassium. However, the poor kinetic performance and severe volume changes during charging/discharging due to the large radius of potassium leading to low capacity and rapid decay. Therefore, development of anode materials with sufficient space and active sites for potassium ion deintercalation and desorption is necessary to ensure structural stability and good electrochemical activity. This study prepared boron-doped pine-cone carbon (BZPC) with 3D interconnected hierarchical porous in ZnCl₂ molten-salt by calcination under high temperature. The hierarchical porous structure promoted the penetration of the electrolyte, improved charge-carrier diffusion, alleviated volume changes during cycling, and increased the number of micropores available for adsorbing potassium ions. In addition, due to B doping, the BZPC material possessed abundant defects and active centers, and a wide interlayer distance, which enhanced the adsorption of K ions and promoted their intercalation and diffusion. When used as the anode of a KIB, BZPC provided a high reversible capacity (223.8 mAh g^-1 at 50 mA g^-1), excellent rate performance, and cycling stability (115.9 mAh g^-1 after 2000 cycles at 1 A g^-1).

Keywords: anodes; biomass carbon; boron doping; molten ZnCl2; pine-cone; potassium-ion batteries.