Microstructure regulation of pitch-based soft carbon anodes by iodine treatment towards high-performance potassium-ion batteries

Chang Liu; Hongjie Zheng; Yuwei Wang; Nan Xiao; Kai Yu; Hui Li; Xu Zhang; Hongcun Bai; Tianyi Ma; Jieshan Qiu

doi:10.1016/j.jcis.2022.01.178

Microstructure regulation of pitch-based soft carbon anodes by iodine treatment towards high-performance potassium-ion batteries

J Colloid Interface Sci. 2022 Jun:615:485-493. doi: 10.1016/j.jcis.2022.01.178. Epub 2022 Jan 31.

Authors

Chang Liu¹, Hongjie Zheng¹, Yuwei Wang², Nan Xiao², Kai Yu¹, Hui Li³, Xu Zhang², Hongcun Bai⁴, Tianyi Ma⁵, Jieshan Qiu⁶

Affiliations

¹ Institute of Clean Energy Chemistry, Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials of Liaoning Province, College of Chemistry, Liaoning University, Shenyang 110036, China.
² State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, China.
³ Institute of Clean Energy Chemistry, Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials of Liaoning Province, College of Chemistry, Liaoning University, Shenyang 110036, China; School of Science, RMIT University, Melbourne, VIC 3000, Australia.
⁴ State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, Ningxia University, Yinchuan, Ningxia 750021, China.
⁵ School of Science, RMIT University, Melbourne, VIC 3000, Australia. Electronic address: tianyima@swin.edu.au.
⁶ State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China. Electronic address: qiujs@mail.buct.edu.cn.

PMID: 35150956
DOI: 10.1016/j.jcis.2022.01.178

Abstract

Soft carbon has been regarded as one of the most promising anode materials for potassium-ion batteries. However, the rearrangement of planar aromatics at high carbonization temperature usually yields a highly graphitized structure, which generally leads to inferior rate and cycle performance. In addition, the role of intrinsic carbon defects on potassium storage has not been well reported yet. In this work, crosslinked pitch-based soft carbon nanosheets have been synthesized through the iodination/dehydroiodination process at low temperature and carbonization with NaCl template. The iodine-treatment efficiently crosslinks the planar aromatics to three-dimensional framework by alkyl-bridged linkages, and reduces the strong π-π interaction during carbonization. This unique microstructure yields an ordered-in-disordered carbon microstructure, enlarged interlayer spacing, and abundant intrinsic defect sites. Benefited from these merits, the optimal sample displays 140% increase of reversible capacity to the pristine pitch-based carbon at 5 A g^-1. Particularly, it also presents 87.4% capacity retention after 1000 cycles at 1 A g^-1. This facile but simple strategy is expected to expand to other high-performance carbon materials and further understand the effect of intrinsic defects for potassium storage and beyond.

Keywords: Carbon anode; Coal tar pitch; Intrinsic carbon defects; Iodine treatment; Microstructure tuning.