Toward Highly Selective Heteroatom Dopants in Hard Carbon with Superior Lithium Storage Performance

Abstract

Hard carbons (HCs) have gained much attention for next-generation high energy density lithium-ion battery (LIB) anode candidates. However, voltage hysteresis, low rate capability, and large initial irreversible capacity severely affect their booming application. Herein, a general strategy is reported to fabricate heterogeneous atom (N/S/P/Se)-doped HC anodes with superb rate capability and cyclic stability based on a three-dimensional (3D) framework and a hierarchical porous structure. The obtained N-doped hard carbon (NHC) exhibits an excellent rate capability of 315 mA h g–1 at 10.0 A g–1 and a long-term cyclic stability of 90.3% capacity retention after 1000 cycles at 3 A g–1. Moreover, the as-constructed pouch cell delivers a high energy density of 483.8 W h kg–1 and fast charging capability. The underlying mechanisms of lithium storage are illustrated by electrochemical kinetic analysis and theoretical calculations. It is demonstrated that heteroatom doping imposes significant effects on adsorption and diffusion for Li+. The versatile strategy in this work opens an avenue for rational design of advanced carbonaceous materials with high performance for LIB applications.

Selenium-doped carbon materials: synthesis and applications for sustainable technologies

“…In an interesting approach, a mixture of KCl/LiCl, glucose, and Na 2 SeO 3 was carbonized at 700 °C to produce Se-doped carbon with a 3D framework and a hierarchical porosity (SSA of 446 m 2 g −1 ). 72 The interlayer spacing of graphenic layers in the produced hard carbon was 0.394 nm. The authors interpreted this as a consequence of the large Se atom size that expands the spacing.…”

“…Doping carbons with heteroatoms such as N, Se, S, or P can modulate Li ion adsorption and diffusion by expanding the interlayer spacing of carbon materials and improving adsorption energy. 72 When selenium-doped rGOs were evaluated for LIBs, they showed better Li storage performance than their undoped counterparts. 36 This was attributed to the improved electrical conductivity.…”