Eggshell‐Assisted Preparation of Mixed Nanoparticles Simultaneously Encapsulated in Carbon Microcubes for Reversible Lithium Storage. (27th December 2017)

• Record Type: Journal Article
• Authors: Meng, Xinghua; Ng, Simon; Ding, Yi; Deng, Da
• Is Part Of: Particle and particle systems characterization. Volume 35:Number 2(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-12-27
• Subjects: core–shell -- eggshell -- in situ carbonization -- lithium‐ion batteries -- mixed nanoparticles; Particles -- Periodicals; 620.43
• DOI: 10.1002/ppsc.201700311
• Languages: English
• ISSNs: 0934-0866

Abstract

Abstract: Nanoparticle‐based electrodes often suffer from poor electrical properties due to high interparticle resistance, as well as low Coulombic efficiency attributed to large surface area induced parasitic reactions. In order to address this issue, a strategy of encapsulating two kinds of nanoparticles of both metal oxide and metallic nanoparticles is attempted, simultaneously, in microscale carbon cubic shells for highly reversible lithium storage. The unique structure is synthesized by simultaneous reactions of (1) decomposition of crystalline Co2 (OH)3 Cl microparticle precursor, synthesized in unique eggshell reactor systems, into nanoparticles, (2) partial reduction of CoO into metallic Co by eggshell membrane, (3) carbon coating by chemical vapor deposition facilitated by presence of catalytic Co with carbon released from the eggshell membrane, and (4) microscale carbon shell formed using the Co2 (OH)3 Cl particles as microtemplates. The carbon shells can prevent the encapsulated mixed nanoparticles from direct contact with electrolyte and reduce undesirable parasitic reactions, and accommodate volumetric variation during cycling. The introduction of metallic Co nanoparticles can reduce interparticle resistance. When evaluated for lithium storage, the unique structures of CoO–Co@C demonstrate superior electrochemical performances in terms of electrode stability and rate performance, as compared to that of pure CoO. Abstract : Eggshell‐assisted preparation of mixed two kinds of nanoparticles simultaneously encapsulated in one hollow carbon microcube is demonstrated. The composite with "two@one" design demonstrates superior electrochemical performance in reversible lithium‐ion storage.