Walnut-inspired microsized porous silicon/graphene core-shell composites for high-performance lithium-ion battery anodes

作     者：Wei Zhai Qing Ai Lina Chen Shiyuan Wei Deping Li Lin Zhang Pengchao Si Jinkui Feng Lijie Ci 

作者机构：SDU & Rice Joint Center for Carbon Nanomaterials Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education) School of Materials Science and Engineering Shondong University Jinan 250061 China 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2017年第10卷第12期

页      面：4274-4283页

核心收录：

学科分类：07[理学] 

基　　金：supported by the 1000 Talent Plan program Key Research Plan of Shandong Province Independent Innovation Foundation of Shandong University the Young Scholars Program of Shandong University 

主　　题：graphene silicon in situ reduction lithium-ion batteries 

摘      要：Silicon is considered an exceptionally promising alternative to the most commonly used material, graphite, as an anode for next-generation lithium-ion batteries, as it has high energy density owing to its high theoretical capacity and abundant storage. Here, microsized walnut-like porous silicon/reduced graphene oxide （P-Si/rGO） core-shell composites are successfully prepared via in situ reduction followed by a dealloying process. The composites show specific capacities of more than 2,100 mAh-g-1 at a current density of 1,000 mA-g-1, 1,600 mAh.g-1 at 2,000 mA-g-1, 1,500 mAh-g 1 at 3,000 mA-g-1, 1,200 mAh-g-1 at 4,000 mA.g-1, and 950 mAh.g~ at 5,000 mA.g-~, and maintain a value of 1,258 mAh.g-~ after 300 cycles at a current density of 1,000 mA-g 1. Their excellent rate performance and cycling stability can be attributed to the unique structural design： 1） The graphene shell dramatically improves the conductivity and stabilizes the solid- electrolyte interface layers; 2） the inner porous structure supplies sufficient space for silicon expansion; 3） the nanostructure of silicon can prevent the pulverization resulting from volume expansion stress. Notably, this in situ reduction method can be applied as a universal formula to coat graphene on almost all types of metals and alloys of various sizes, shapes, and compositions without adding any reagents to afford energy storage materials, graphene-based catalytic materials, graphene-enhanced composites, etc.