Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences , 315201 Ningbo , P.R. China.
University of Chinese Academy of Sciences , 100049 Beijing , P.R. China.
ACS Nano. 2018 Mar 27;12(3):2809-2817. doi: 10.1021/acsnano.8b00073. Epub 2018 Mar 12.
High ionic conductivity electrolyte and intimate interfacial contact are crucial factors to realize high-performance all-solid-state sodium batteries. NaPSSe electrolyte with reduced particle size of 500 nm is first synthesized by a simple liquid-phase method and exhibits a high ionic conductivity of 1.21 × 10 S cm, which is comparable with that synthesized with a solid-state reaction. Meanwhile, a general interfacial architecture, that is, NaPSSe electrolyte uniformly anchored on FeS nanorods, is designed and successfully prepared by an in situ liquid-phase coating approach, forming core-shell structured FeS@NaPSSe nanorods and thus realizing an intimate contact interface. The FeS@NaPSSe/NaPSSe/Na all-solid-state sodium battery demonstrates high specific capacity and excellent rate capability at room temperature, showing reversible discharge capacities of 899.2, 795.5, 655.1, 437.9, and 300.4 mAh g at current densities of 20, 50, 100, 150, and 200 mA g, respectively. The obtained all-solid-state sodium batteries show very high energy and power densities up to 910.6 Wh kg and 201.6 W kg based on the mass of FeS at current densities of 20 and 200 mA g, respectively. Moreover, the reaction mechanism of FeS is confirmed by means of ex situ X-ray diffraction techniques, showing that partially reversible reaction occurs in the FeS electrode after the second cycle, which gives the obtained all-solid-state sodium battery an exceptional cycling stability, exhibiting a high capacity of 494.3 mAh g after cycling at 100 mA g for 100 cycles. This contribution provides a strategy for designing high-performance room temperature all-solid-state sodium battery.
高离子电导率电解质和紧密的界面接触是实现高性能全固态钠电池的关键因素。通过简单的液相法首次合成了粒径为 500nm 的 NaPSSe 电解质，其离子电导率高达 1.21×10-3S cm，可与固态反应合成的相媲美。同时，通过原位液相包覆法设计并成功制备了一种通用的界面结构，即 NaPSSe 电解质均匀锚定在 FeS 纳米棒上，形成核壳结构的 FeS@NaPSSe 纳米棒，从而实现了紧密的界面接触。室温下，FeS@NaPSSe/NaPSSe/Na 全固态钠电池表现出高比容量和优异的倍率性能，在 20、50、100、150 和 200mA g-1 的电流密度下，可逆放电容量分别为 899.2、795.5、655.1、437.9 和 300.4mAh g-1。基于 20mA g-1 和 200mA g-1 电流密度下 FeS 的质量，获得的全固态钠电池具有非常高的能量和功率密度，分别高达 910.6Wh kg-1 和 201.6W kg-1。此外，通过原位 X 射线衍射技术证实了 FeS 的反应机理，表明在第二次循环后 FeS 电极中发生了部分可逆反应，这使得所获得的全固态钠电池具有出色的循环稳定性，在 100mA g-1 下循环 100 次后，容量高达 494.3mAh g-1。该研究为设计高性能室温全固态钠电池提供了一种策略。
