Control over large-volume changes of lithium battery anodes via active–inactive metal alloy embedded in porous carbon. (July 2015)

• Record Type: Journal Article
• Authors: Mahmood, Nasir; Zhu, Jinghan; Rehman, Sarish; Li, Quan; Hou, Yanglong
• Is Part Of: Nano energy. Volume 15(2015:Jul.)
• Page Start: 755
• Page End: 765
• Publication Date: 2015-07
• Subjects: Lithium ion battery -- CoSn alloy -- Long cyclic life -- Large volume changes -- High capacity; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2015.05.035
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Large volume changes and limited access to redox sites of high capacity anode materials are great challenges. Although, various strategies were adopted but still results are far from required values for their practical usage. Here, we have designed a unique structure to prevent surface reaction and structural disintegration meanwhile intrinsic conductivity is improved to involve all redox sites in conversion reaction. CoSn x @C–PAn hybrid was synthesized through aqueous chemical route, Co doping in tin make accessible all redox sites by faster conduction of electrons while its hard nature relaxes internal stress, carbon shell prevents surface reaction and brings well control on solid electrolyte interface (SEI) film by maintaining barrier between electrode surface and electrolyte and nitrogen doped porous carbon provides faster diffusion of Li + deep in electrode make possible high mass loadings and conduction highway for electrons. Furthermore, porous carbon also provides room to compensate volume expansion and keeps electrode structure stable. Because of its unique structure hybrid shows excellent reversible capacity of 2044 mAh/g (retention 100%) with mass loading of 3.8 mg/cm 2 along with long cyclic life up to 1000 cycles and bears high rate capability (20 A/g).We believe that present study makes possible the use of high capacity materials in applications. graphical abstract: Highlights: A unique strategy was developed to control the large volume changes of electrode materials via active-inactive metal alloy covered by carbon coat and embedded in NPGC matrix. The Co doping in the core of Sn NPs increases intrinsic conductivity to access all redox sites and compensate internal stresses, while carbon coat protects surface reactions. Carbon matrix provides highway for faster electronic and ionic conduction and fused aromatic carbon (C6 ) make possible large storage of Li + . The hybrid delivered excellent capacity (2044 mAh/g) at high mass loading of 3.8 mg/cm 2, long cyclic life up to 1000 cycles and high rate capability at 20 A/g.