Nitrogen-doped carbon nanotube-buffered FeSe2 anodes for fast-charging and high-capacity lithium storage
By Liang, Tian; Wang, Huanwen; Wang, Rui; He, Beibei; Gong, Yansheng; Yan, Chunjie
Published in Electrochimica Acta
2021
Abstract
Fast−charging and high−capacity have become indispensable requirements for next−generation energy storage systems. However, large−scale fabrication of high−capacity anode materials for fast Li+ storage remains a huge challenge. Herein, natural hematite is employed as the starting material to achieve scalable synthesis of nitrogen−doped carbon nanotube−buffered FeSe2 (FeSe2@N−CNT) through a facile catalyzing & selenizing process. The readily−available raw materials and simple processing procedures are suitable to industrial−level batch production. In this FeSe2@N−CNT composite, the FeSe2 particles are efficiently encapsulated into the interwoven carbon nanotube network, which can enlarge the contact area with electrolyte, enhance the electrical conductivity, shorten the Li+/e– diffusion length and buffer the drastic volume variation of FeSe2 during lithiation/delithiation. As an anode material of lithium ion batteries (LIBs), the FeSe2@N−CNT electrode delivers a significantly high specific capacity of 806 mAh g−1 at a high current density of 20 A g−1 (relative to 915 mAh g−1 at 0.1 A g−1). More importantly, long−term cycle stability (953 mAh g−1 after 1500 cycles at 10 A g−1) is achieved, which outperforms most FeSe2−based Li+ storage anodes reported so far. The easy−to−implement mass production and the high Li+ storage property enable FeSe2@N−CNT as a promising candidate as a commercial anode for LIBs.