Hollow carbon microbox from acetylacetone as anode material for sodium-ion batteries

• 来源期刊: 能源化学
• 年，卷（期）: 2020,（12）
• 页码范围: 293-302
• 页数: 10页
• 语种: 英文

摘要

Carbon-based materials have attracted much interest as one of the promising anodes for sodium-ion bat-teries.However,low utilization of electrolyte and slow ion-transfer rate during electrochemical process hinder the further application of traditional bulk carbon.In order to enhance the diffusion kinetics and maintain the reversibility,hierarchical hollow carbon microbox was successfully prepared through a tun-able bottom-up self-template routine for sodium-ion batteries.During annealing process,the morphol-ogy construction and activation happened synchronously.Based on that,a range of cross-linked porous nanosheet and hollow microbox were attained by manipulating reactant condition.The generation of tex-ture and physical property are analyzed and are established linkages related to the electrochemical be-havior.As results depicted in kinetic exploration and simulation based on cyclic voltammetry,the surface-controlled electrochemical behavior gradually turns to be the diffusion-controlled behavior as the hollow microbox evolves to porous nanosheet.The probable reason is that the rational microstructure/texture design leads to the accelerated diffusion kinetic procedure and the reduced concentration difference po-larization.Sodium storage mechanism was deduced as reversible binding of Na-ions with local defects,including vacancies on sp2 graphitic layers,at the edges of flakes and other structural defects instead of intercalation.Bestowed by the morphology design,the broad pore width distribution,abundant de-fects/active sites and surface functionality,hollow microbox electrode delivers great electrochemical per-formances.This work is expected to propose a novel and effective strategy to prepare tunable hierarchical hollow carbon microbox and induce the fast kinetic of carbon anode material.