Quasi-Topological Intercalation Mechanism of Bi0.67NbS2 Enabling 100 C Fast-Charging for Sodium-Ion Batteries
Quasi-Topological Intercalation Mechanism of Bi0.67NbS2 Enabling 100 C Fast-Charging for Sodium-Ion Batteries
复制标题
DOI：
10.1002/aenm.202300790
复制
发表时间：
2023-05-17
影响因子：
27.8
通讯作者：
Huang, Fuqiang
中科院分区：
文献类型：
--
作者：
Lv, Zhuoran;Xu, Hengyue;Huang, Fuqiang
具有高容量的合金型铋已成为钠离子电池的有前途的阳极，但存在体积膨胀大和连续粉化的问题。本文提出了一种配位约束策略，即通过有利于重构的线性配位键将Bi原子化学限制在插层主体框架中，从而实现了一种新的准拓扑插层机制。具体地，合成了微米尺寸的Bi 0.67NbS2，其中Bi原子与NbS 2的层间层中的两个S原子线性配位。稳健的Nb-S主体框架提供快速离子/电子扩散通道并缓冲Na+插入的体积膨胀，赋予Bi 0.67NbS2较低的能垒（0.141 eV对Bi的0.504 eV）。原位和非原位表征表明，Bi原子与Na+通过固溶过程形成合金，并在脱合金后受到重新形成的Bi-S键的约束，实现了Bi 0.67NbS2晶相的完全恢复，避免了Bi原子的迁移和聚集。相应地，Bi 0.67NbS2阳极在1C下提供325 mAh g（-1）的可逆容量，并且在100C下超过25000次循环时提供226 mAh g（-1）的非凡的超高倍率稳定性。协调模式调制诱导的准拓扑插层机制有望有助于快速充电电池的实际电极设计。
Alloying-type bismuth with high volumetric capacity has emerged as a promising anode for sodium-ion batteries but suffers from large volume expansion and continuous pulverization. Herein, a coordination constraint strategy is proposed, that is, chemically confining atomic Bi in an intercalation host framework via reconstruction-favorable linear coordination bonds, enabling a novel quasi-topological intercalation mechanism. Specifically, micron-sized Bi0.67NbS2 is synthesized, in which the Bi atom is linearly coordinated with two S atoms in the interlayer of NbS2. The robust Nb-S host framework provides fast ion/electron diffusion channels and buffers the volume expansion of Na+ insertion, endowing Bi0.67NbS2 with a lower energy barrier (0.141 vs. 0.504 eV of Bi). In situ and ex situ characterizations reveal that Bi atom alloys with Na+ via a solid-solution process and is constrained by the reconstructed Bi-S bonds after dealloying, realizing complete recovery of crystalline Bi0.67NbS2 phase to avoid the migration and aggregation of atomic Bi. Accordingly, the Bi0.67NbS2 anode delivers a reversible capacity of 325 mAh g(-1) at 1 C and an extraordinary ultrahigh-rate stability of 226 mAh g(-1) at 100 C over 25 000 cycles. The proposed quasi-topological intercalation mechanism induced by coordinated mode modulation is expected to be be conducive to the practical electrode design for fast-charging batteries.