低温沉积亲锌碳层用于长寿命锌金属电池

Low-temperature deposition of a zincophilic carbon layer for long-life zinc metal batteries

  • 摘要: 水系锌金属电池(ZMBs)具有环境友好、成本低廉的特点,可用于电网规模储能,但具有循环寿命较短的缺点,其主要原因在于锌金属负极在弱酸性水系电解液中的可逆性较差。本文通过三聚氰胺(ME)和三聚氰酸(CA)组装的氢键超分子框架(HSFs)的上游热解,在Zn箔上低温沉积了亲锌碳(ZC)层。重要的是,ZC层中的亲锌基团(如C=O和C=N)可引导均匀的锌成核/沉积,消除枝晶和副反应。因此,组装的对称电池(ZC@Zn//ZC@Zn)在1 mA cm−2和1 mAh cm−2的条件下可达到2500 h的长循环寿命,明显优于裸锌负极(180 h)。此外,在2 A g−1电流密度下,组装的ZC@Zn//V2O5全电池循环1200次后比容量仍高达174 mAh g−1,高于Zn//V2O5全电池(100 mAh g−1)。本文开发的低温沉积ZC层策略为构建高性能锌金属负极提供了新思路。

     

    Abstract: Aqueous zinc metal batteries (ZMBs) with environmental benign and low cost can be used for grid-scale energy storage, but have shortcomings of short cycling life mainly due to inferior reversibility of zinc metal anodes in mild aqueous electrolytes. Herein, a zincophilic carbon (ZC) layer is effectively deposited on Zn metal foil at low temperature of 450 °C via up-stream pyrolysis of a hydrogen-bonded supramolecular substances frameworks (HSFs), which is assembled by melamine (ME) and cyanuric acid (CA). Importantly, the zincophilic groups (e.g., C=O and C=N) in the ZC layer can guide uniform zinc plating/stripping and eliminate dendrites and side reactions. Therefore, the assembled symmetrical batteries (ZC@Zn//ZC@Zn) achieve a long-term serve time of 2500 h at 1 mA cm−2 and 1 mAh cm−2, obviously longer than that of bare Zn anodes (180 h). In addition, the assembled ZC@Zn//V2O5 full batteries exhibit a higher capacity of 174 mAh g−1 after 1200 cycles at 2 A g−1 than the Zn//V2O5 counterpart (100 mAh g−1). The developed strategy for the low-temperature deposition of ZC layer paves a new way to construct advanced zinc metal anodes for advanced ZMBs.

     

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