Two Birds with One Stone: FeS<sub>2</sub>@C Yolk–Shell Composite for High-Performance Sodium-Ion Energy Storage and Electromagnetic Wave Absorption
Zengming Man, Peng Li, Peng Li, Dong Zhou, Yizhou Wang, Xiaohui Liang, Rui Zang, Pengxin Li, Pengxin Li, Yuqi Zuo, Yeng Ming Lam, Guoxiu Wang
Abstract
Cost-effective material with a rational design is significant for both sodium-ion batteries (SIBs) and electromagnetic wave (EMW) absorption. Herein, we report an elaborate yolk–shell FeS2@C nanocomposite as a promising material for application in both SIBs and EMW absorption. When applied as an anode material in SIBs, the yolk–shell structure not only facilitates a fast electron transport and shortens Na ion diffusion paths but also eases the huge volume change of FeS2 during repeated discharge/charge processes. The as-developed FeS2@C exhibits a high specific capacity of 616 mA h g–1 after 100 cycles at 0.1 A g–1 with excellent rate performance. Furthermore, owing to the significant cavity and interfacial effects enabled by yolk–shell structuring, the FeS2@C nanocomposite delivers excellent EMW absorption properties with a strong reflection loss (−45 dB with 1.45 mm matching thickness) and a broad 15.4 GHz bandwidth. This work inspires the development of high-performance bifunctional materials.