Ren Tiantian, Xu Ao, Chen Chunxia, Wang Yangyang, Zhang Yuhang, Wang Hui, Liu Xiaojie
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi'an, 710127, P. R. China.
Small. 2024 Nov;20(48):e2405719. doi: 10.1002/smll.202405719. Epub 2024 Sep 2.
NaV(PO)(NVP), as a representative sodium superionic conductor with a stable polyanion framework, is considered a cathode candidate for aqueous zinc-ion batteries attributed to their high discharge platform and open 3D structure. Nevertheless, the structural stability of NVP and the cathode-electrolyte interphase (CEI) layer formed on NVP can be deteriorated by the aqueous electrolyte to a certain extent, which will result in slow Zn migration. To solve these problems, doping Si elements to NVP and adding sodium acetate (NaAc) to the electrolyte are utilized as a synergistic regulation route to enable a highly stable CEI with rapid Zn migration. In this regard, Ac competitively takes part in the solvation structure of Zn in aqueous electrolyte, weakening the interaction between water and Zn, and meanwhile a highly stable CEI is formed to avoid structural damage and enable rapid Zn migration. The NVPS/C@rGO electrode exhibits a notable capacity of 115.5 mAh g at a current density of 50 mA g in the mixed electrolyte (3 M ZnOTF+3 M NaAc). Eventually, a collapsible "sandwich" soft pack battery is designed and fabricated and can be used to power small fans and LEDs, which proves the practical application of aqueous zinc-ion batteries in flexible batteries.
NaV(PO)(NVP)作为具有稳定聚阴离子骨架的代表性钠超离子导体，因其高放电平台和开放的三维结构而被认为是水系锌离子电池的阴极候选材料。然而，NVP的结构稳定性以及在NVP上形成的阴极-电解质界面（CEI）层会在一定程度上被水系电解质破坏，这将导致锌迁移缓慢。为了解决这些问题，将硅元素掺杂到NVP中并向电解质中添加醋酸钠（NaAc）作为一种协同调控途径，以实现具有快速锌迁移的高度稳定的CEI。在这方面，Ac竞争性地参与水系电解质中锌的溶剂化结构，减弱水与锌之间的相互作用，同时形成高度稳定的CEI以避免结构破坏并实现快速锌迁移。NVPS/C@rGO电极在混合电解质（3 M ZnOTF + 3 M NaAc）中，在50 mA g的电流密度下表现出115.5 mAh g的显著容量。最终，设计并制造了一种可折叠的“三明治”软包电池，可用于为小型风扇和发光二极管供电，这证明了水系锌离子电池在柔性电池中的实际应用。
