Sb Nanoparticles Embedded in a Nitrogen‐Doped Carbon Matrix with Tuned Voids and Interfacial Bonds for High‐Rate Lithium Storage

Abstract

AbstractThough metal based electrodes have good resistivity, their huge volume changes upon lithiation and interparticle contact resistance should be carefully stressed to achieve high rate lithium storage performances. A yolk‐hollow structure with a continuous conductive framework would solve above problems. Inspired by the yolk‐hollow structure and functions of watermelon‐flesh, we fabricated Sb/amorphous carbon/graphene nanocomposites, in which Sb nanoparticles are formed in‐situ inside the carbon nanocages that are homogeneously decorated on graphene and distributed in a continuous N‐doped amorphous carbon matrix. The generated Sb−O−C bonds improve the electron transfer rate; the carbon nanocages as mini‐electrochemical nanoreactors sustain the volume change; the conductive matrix reduces the contact resistance. The optimized nanocomposite delivers a remarkable reversible capacity of 592 mA h g−1 at 500 mA g−1 with a good cyclability for 400 cycles. A high capacity of 413 mA h g−1 is retained even after 700 cycles at 1000 mA g−1. Such a long cycle life at the high current density has rarely been reported so far for Sb‐based lithium‐ion battery anodes.