Boosting the Cycling Stability of Aqueous Flexible Zn Batteries via F Doping in Nickel-Cobalt Carbonate Hydroxide Cathode
Boosting the Cycling Stability of Aqueous Flexible Zn Batteries via F Doping in Nickel-Cobalt Carbonate Hydroxide Cathode
复制标题
通过在氢氧化镍-碳酸钴正极中掺氟提高水系柔性锌电池的循环稳定性
DOI：
10.1002/smll.202001935
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发表时间：
2020-06-30
期刊：
影响因子：
13.3
通讯作者：
Li, Hongfei
中科院分区：
文献类型：
--
作者：
Li, Xuejin;Tang, Yongchao;Li, Hongfei
可再充电Zn电池的阴极通常在重复充电/放电循环期间面临不可逆相变、结构崩溃和体积膨胀的问题，这导致增加的转移电阻和差的长期循环稳定性。在此，开发了一种简单的F掺杂策略来提高碳酸钴镍氢氧化物（NiCo-CH）阴极的循环稳定性。由于NiCo-CH-F具有极高的电负性，F的引入显著提高了NiCo-CH-F的相稳定性、形貌稳定性和电导率。同时还引入了有利于阴极电化学性能的相界面和非晶态微区。得益于这些特性，NiCo-CH-F具有高容量（245 mA h g（-1））、出色的倍率性能（8 A g（-1）时保持率为64%）和出色的循环稳定性（10000次循环后保持率为90%）。此外，准固态电池还表现出上级的循环稳定性（在7200次循环后保持90%）和期望的柔性。本工作为提高锌水溶液电池正极材料的循环稳定性提供了一种通用策略。
Cathodes of rechargeable Zn batteries typically face the issues of irreversible phase transformation, structure collapse, and volume expansion during repeated charge/discharge cycles, which result in an increased transfer resistance and poor long-term cycling stability. Herein, a facile F doping strategy is developed to boost the cycling stability of nickel cobalt carbonate hydroxide (NiCo-CH) cathode. Benefiting from the extremely high electronegativity, the phase and morphology stabilities as well as the electrical conductivity of NiCo-CH are remarkably enhanced by F incorporation (NiCo-CH-F). Phase interface and amorphous microdomains are also introduced, which are favorable for the electrochemical performance of cathode. Benefiting from these features, NiCo-CH-F delivers a high capacity (245 mA h g(-1)), excellent rate capability (64% retention at 8 A g(-1)), and outstanding cycling stability (maintains 90% after 10 000 cycles). Moreover, the quasi-solid-state battery also manifests superior cycling stability (maintains 90% after 7200 cycles) and desirable flexibility. This work offers a general strategy to boost the cycling stability of cathode materials for aqueous Zn batteries.