Li Xuejin, Tang Yongchao, Zhu Jiaxiong, Lv Haiming, Zhao Lianming, Wang Wenlong, Zhi Chunyi, Li Hongfei
Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China.
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, CAS, Beijing, 100190, China.
Small. 2020 Aug;16(31):e2001935. doi: 10.1002/smll.202001935. Epub 2020 Jun 30.
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 ), excellent rate capability (64% retention at 8 A g ), 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.
可充电锌电池的阴极在反复充放电循环过程中通常面临不可逆相变、结构坍塌和体积膨胀等问题，这些问题会导致转移电阻增加和长期循环稳定性差。在此，开发了一种简便的氟掺杂策略来提高氢氧化镍钴碳酸酯（NiCo-CH）阴极的循环稳定性。受益于极高的电负性，通过氟掺入（NiCo-CH-F），NiCo-CH的相稳定性、形态稳定性以及电导率都得到了显著提高。还引入了相界面和非晶微区，这有利于阴极的电化学性能。受益于这些特性，NiCo-CH-F具有高容量（245 mA h g）、优异的倍率性能（在8 A g下保持64%）和出色的循环稳定性（在10000次循环后保持90%）。此外，准固态电池也表现出优异的循环稳定性（在7200次循环后保持90%）和良好的柔韧性。这项工作为提高水系锌电池阴极材料的循环稳定性提供了一种通用策略。
