Carbon Yarn ‐Ball‐Entangled SiO2 Anode with Excellent Electrochemical Performance for Lithium‐Ion Batteries

Nanoscale SiO2 closely adheres to entangled carbon wires, creating a micrometer-sized yarn-ball-like secondary particle. The carbon yarn-ball structure provides a network of electron conduction highways and accommodates the large volume expansion of SiO2. Greatly enhanced conductivity and structural stability give rise to excellent electrochemical performance during high-rate charge/discharge cycling. AbstractVarious nanoscale SiO2 and their composites have demonstrated superior electrochemical performance as anodes for lithium-ion batteries. However, both the battery production and real applications require the integration of nanoscale SiO2 into micrometer-sized secondary particles while preserving their excellent stability and conductivity, which remains a great challenge. In this work, a unique carbon yarn-ball structure is successfully synthesized that entangles nanoscale SiO2 together to build a micrometer-sized secondary particle. The hook-like carbon wires closely adhere to individual SiO2 nanoparticles, which constitute the basic unit of the yarn-ball structure. The entangled carbon wires create a network of electron conduction highways for SiO2, and the yarn-ball structure provides a resilient 3D matrix that can effectively buffer the anisotropic volume changes of SiO2 during Li ion insertion/extraction. Under 0.1 A g−1, the carbon yarn-ball-entangled SiO2 can deliver a 1297 mAh g−1 discharge capacity with a small irreversible capacity of 82 mAh g−1. The entang...

Source: Small - October 16, 2021 Category: Nanotechnology Authors: Dan Wang, Tongshuai Wang, Miao He, Ting Wang, Hailong Wang Tags: Research Article Source Type: research