Boosting the Na‐Ion Conductivity in the Cluster‐Ion Based Anti‐Perovskite Na2BH4NH2
Boosting the Na‐Ion Conductivity in the Cluster‐Ion Based Anti‐Perovskite Na2BH4NH2
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DOI：
10.1002/adfm.202301635
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发表时间：
2023-04
影响因子：
19
通讯作者：
Ruohan Jiang;Changsheng Song;Jinghao Yang;Jie Zhao;Fang Fang-Fang;Yun Song;Dalin Sun;Fei Wang
中科院分区：
文献类型：
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作者：
Ruohan Jiang;Changsheng Song;Jinghao Yang;Jie Zhao;Fang Fang-Fang;Yun Song;Dalin Sun;Fei Wang
固态钠离子/金属电池（SSSB）对于下一代储能系统是非常理想的，而对非常有限的钠离子固态电解质进行了探索。基于硼氢化物的固体电解质由于其低氧化还原电位、低杨氏模量以及对碱金属的高稳定性而有望实现高能量密度目标。然而，硼氢化物基电解质的最大挑战是低离子电导率。在这项研究中，探索了一种富含空位缺陷的反钙钛矿固态电解质（SSE）材料Na 2BH 4 NH 2，以解决上述问题。得益于富空位缺陷，在90 °C下实现了7.56 × 10−4 S cm−1的高离子电导率和0.67 eV的低Na+迁移活化能。关于NaSn|硼氢化钠|NaSn对称电池循环，电流密度为0.1 mA cm-2，持续500 h。此外，Na 2BH 4 NH 2电解质的普遍性通过TiS 2阴极验证，表明Na 2BH 4 NH 2与电极材料具有良好的相容性。这些优异的性能表明，通过形成空位缺陷来提高离子电导率是一种可行的策略，从而导致进一步开发具有上级性能的固体电解质。
Solid‐state sodium‐ion/metal batteries (SSSBs) are highly desirable for next‐generation energy storage systems, while very limited Na‐ion solid‐state electrolytes are explored. The borohydride‐based solid electrolytes are expected to achieve the high energy density target, due to their low redox potential, low Young's modulus as well as high stability toward alkali metals. However, the biggest challenge of borohydride‐based electrolyte is the low ionic conductivity. In this study, an anti‐perovskite solid‐state electrolyte (SSE) material rich in vacancy defects is explored, Na2BH4NH2, to solve above problems. Benefitting from rich vacancy defects, a high ionic conductivity of 7.56 × 10−4 S cm−1 with a low activation energy for Na+ migration of 0.67 eV at 90 °C are achieved. The NaSn|Na2BH4NH2|NaSn symmetric cell cycles at a current density of 0.1 mA cm−2 for 500 h. Moreover, the universality of Na2BH4NH2 electrolyte is verified by TiS2 cathode, indicating that Na2BH4NH2 has good compatibility with electrode material. These outstanding performances suggest that it is a viable strategy to increase the ionic conductivity by forming vacancy defects, leading to the further development of solid electrolytes with superior properties.