Double Coating of Micron‐Sized Silicon by TiN@NC for High‐Performance Anode in Lithium‐Ion Batteries

• Published in: Energy technology (Weinheim, Germany) Germany), 2019-09, Vol.7 (9), p.n/a
• Main Authors: Liu, Qiaoyun, Pang, Chunlei, Chen, Weilun, Rao, Zhixiang, Lu, Haoqi, Xue, Lihong, Zhang, Wuxing
• Format: Article
• Language: English
• Subjects: Anodes; Coated electrodes; double-layer coating; Electrochemistry; Lithium; Lithium-ion batteries; Rechargeable batteries; Silicon; tape casting
• ISSN: 2194-4288; 2194-4296
• DOI: 10.1002/ente.201900487

Micron‐sized Si particles are successfully coated by TiN and N‐doped hard carbon (NC) via the combination of the solution method and the tape‐casting method. The double‐coated Si@TiN@NC electrode exhibits excellent electrochemical stability and rate capability, which delivers a reversible capacity of 1024 mAh g−1 at a current density of 4 A g−1 after 550 cycles, corresponding to a capacity retention of 85%. Even at 8 A g−1, the capacity still maintains 1087 mAh g−1. Further investigation shows that the electrochemical enhancement of Si@TiN@NC is mainly attributed to the buffering effect of NC, and the excellent electronic conductivity and mechanical stability of TiN. The TiN@NC double‐layer coating structure provides a new strategy for the design of high‐performance silicon anode in lithium ion batteries (LIBs). Furthermore, the tape‐casting method is a promising way to massively produce silicon‐based composites. The double‐coated Si@TiN@NC composite exhibits excellent lithium storage performance due to the buffering effect of N‐doped hard carbon (NC) and the excellent electronic conductivity and mechanical stability of TiN.