Electrical Conductivity Adjustment for Interface Capacitive‐Like Storage in Sodium‐Ion Battery
Electrical Conductivity Adjustment for Interface Capacitive‐Like Storage in Sodium‐Ion Battery
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DOI：
10.1002/adfm.202101081
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发表时间：
2021-04
影响因子：
19
通讯作者：
Qianwen Li;Han Wang;Xinfeng Tang;Minghong Zhou;Huaping Zhao;Yang Xu;Wei Xiao;Y. Lei
中科院分区：
文献类型：
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作者：
Qianwen Li;Han Wang;Xinfeng Tang;Minghong Zhou;Huaping Zhao;Yang Xu;Wei Xiao;Y. Lei
钠离子电池（SIB）对于电网规模的储能具有重要意义。然而，大半径的Na离子增加了离子嵌入的难度，阻碍了快速充放电时的电化学性能。传统的提高速率性能的策略集中在离子扩散的优化上。通过调整电极的电导率来改善界面电容式存储也有望结合电池的高能量密度和电容器的高功率密度的特点。受这一概念的启发，氧化物-金属夹层3D有序大孔结构（3DOM）作为高速率sib的优越阳极候选者脱颖而出。以Ni - TiO2夹层3DOM为概念验证，锐钛矿TiO2在50 mA g - 1下循环100次后，在半电池中提供233.3 mAh g - 1的可逆容量，在全电池中提供210.1 mAh g - 1的可逆容量。在5000 mA g−1的高充放电倍率下，半电池可获得104.4 mAh g−1，满电池可获得68 mAh g−1，并具有令人满意的稳定性。深入的电化学动力学分析表明，占主导地位的界面电容式存储能够超快速地吸收和释放Na离子。这种对sib电导率和速率性能之间的理解有望指导未来的设计，以实现有效的能量存储。
Sodium‐ion battery (SIB) is significant for grid‐scale energy storage. However, a large radius of Na ions raises the difficulties of ion intercalation, hindering the electrochemical performance during fast charge/discharge. Conventional strategies to promote rate performance focus on the optimization of ion diffusion. Improving interface capacitive‐like storage by tuning the electrical conductivity of electrodes is also expected to combine the features of the high energy density of batteries and the high power density of capacitors. Inspired by this concept, an oxide‐metal sandwich 3D‐ordered macroporous architecture (3DOM) stands out as a superior anode candidate for high‐rate SIBs. Taking Ni‐TiO2 sandwich 3DOM as a proof‐of‐concept, anatase TiO2 delivers a reversible capacity of 233.3 mAh g−1 in half‐cells and 210.1 mAh g−1 in full‐cells after 100 cycles at 50 mA g−1. At the high charge/discharge rate of 5000 mA g−1, 104.4 mAh g−1 in half‐cells and 68 mAh g−1 in full‐cells can also be obtained with satisfying stability. In‐depth analysis of electrochemical kinetics evidence that the dominated interface capacitive‐like storage enables ultrafast uptaking and releasing of Na‐ions. This understanding between electrical conductivity and rate performance of SIBs is expected to guild future design to realize effective energy storage.