Ultrafast, Highly Reversible, and Cycle-Stable Lithium Storage Boosted by Pseudocapacitance in Sn-Based Alloying Anodes
Ultrafast, Highly Reversible, and Cycle-Stable Lithium Storage Boosted by Pseudocapacitance in Sn-Based Alloying Anodes
复制标题
锡基合金阳极中的赝电容增强了超快、高度可逆和循环稳定的锂存储
DOI：
10.1002/adma.201606499
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发表时间：
2017-12-27
影响因子：
29.4
通讯作者：
Yan, Mi
中科院分区：
文献类型：
--
作者：
Jiang, Yinzhu;Li, Yong;Yan, Mi
提高功率密度是当前锂离子电池面临的主要挑战之一。具有合适电势窗口的合金阳极在追求超快和高度可逆的锂存储以实现高功率/能量锂离子电池方面处于最前沿。在本文中，超快锂存储在锡基纳米复合材料阳极被证明，这是由赝电容受益于Fe/Sn/Li 2 O的高度互连的界面的高分数。通过调整合金化/去合金化反应在0.005- 1.2V范围内的电压窗口，这种Sn基纳米复合材料阳极实现了同时的电化学速率能力、超长循环性能和接近100%的库仑效率。纳米复合材料阳极在1A g（-1）下提供高可逆容量（约420 mAh g（-1））超过1200次循环，对应于每个循环仅0.016%的容量衰减。在80 A·g（-1）的恒流密度下，可逆容量保持在350 mAh·g（-1），容量保持率为1 A·g（-1）的67.3%。Sn基纳米复合阳极材料中的赝电容锂储存和空间受限的电化学反应的这种组合可以为开发高功率/能量和长寿命的锂离子电池铺平道路。
Boosting power density is one of the primary challenges that current lithium ion batteries face. Alloying anodes that possess suitable potential windows stand at the forefront in pursuing ultrafast and highly reversible lithium storage to achieve high power/energy lithium ion batteries. Herein, ultrafast lithium storage in Sn-based nanocomposite anodes is demonstrated, which is boosted by pseudocapacitance benefitting from a high fraction of highly interconnected interfaces of Fe/Sn/Li2O. By tailoring the voltage window in the range of 0.005-1.2 V for the alloying/dealloying reactions, such Sn-based nanocomposite anodes achieve simultaneous ultrahigh rate capability, superlong cycling performance, and close-to-100% Coulombic efficiency. The nanocomposite anode delivers a high reversible capacity (approximate to 420 mAh g(-1)) at 1 A g(-1) for more than 1200 cycles, corresponding to only 0.016% per cycle of capacity decay. A reversible capacity of 350 mAh g(-1) can be maintained at an ultrahigh current density of 80 A g(-1), with 67.3% capacity retention relative to the capacity at 1 A g(-1). This combination of pseudocapacitive lithium storage and spatially confined electrochemical reactions in Sn-based nanocomposite anode materials may pave the way for the development of high power/energy and long life lithium ion batteries.