The recent progress of pitch-based carbon anodes in sodium-ion batteries

Sodium-ion batteries(SIBs)have attracted significant attentions as promising alternatives to lithium-ion batteries for large-scale energy storage applications.Here carbon materials are considered as the most competitive anodes for SIBs based on their low-cost,abundant availability and excellent structural stability.Pitch,with high carbon content and low cost,is an ideal raw precursor to prepare carbon materials for large-scale applications.Nevertheless,the microstructures of pitch-based carbon are highly ordered with smaller interlayer distances,which are unfavorable for Na ion storage.Many efforts have been made to improve the sodium storage performance of pitch-based carbon materials.This review summarizes the recent progress about the application of pitch-based carbons for SIBs anodes in the context of carbon’s morphology and structure regulation strategies,including morphology adjustment,heteroatoms doping,fabricating heterostructures,and the increase of the degree of disorder.Besides,the advantages,present challenges,and possible solutions to current issues in pitch-based carbon anode are discussed,with the highlight of future research directions.This review will provide a deep insight into the development of low-cost and high-performance pitch-based carbon anode for SIBs.

3D crumbled MXene for high-performance supercapacitors

MXene materials have recently attracted considerable attention in energy storage application owing to their metallic conductivity,2D structure and tunable surface terminations.However,the restacking of 2D MXene nanosheets hinders the ion transport and accessibility to the surface,resulting in adverse effect on their electrochemical performances.Here,with the assistance of hexamethylenetetramine(C6H12N4),2DTi3C2Tx MXene nanosheets were fabricated into a 3D architecture with crumbled and porous structure through an electrostatic self-assembly followed by annealing.The resultant 3D structure can expose massive active sites and facilitates the ion transport,which is beneficial for sufficient utilization of the outstanding superiorities of the MXene.Therefore,as a pseudocapacitive material,the 3D crumpled and porous Ti3C2Tx MXene shows a gravimetric capacitance of 333 F/g at 1 A/g,and maintains 261 F/g and 132 F/g at ultrahigh current densities of 100 A/g and 1000 A/g,respectively,revealing promising potential for application in supercapacitors.