物理化学学报 >> 2022, Vol. 38 >> Issue (11): 2204048.doi: 10.3866/PKU.WHXB202204048

所属专题： 新锐科学家专刊

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碱性电解液中K3[Fe(CN)6]在锌阳极上的自发还原和吸附延长锌镍电池的循环寿命

沈沅灏1, 王擎宇1, 刘杰1, 钟澄1,2,*(), 胡文彬1,2   

  1. 1 天津大学材料科学与工程学院, 先进陶瓷与加工技术教育部重点实验室, 天津复合材料与功能材料化重点实验室, 天津 300072
    2 天津大学-新加坡国立大学福州联合学院, 天津大学国际校区, 福州 350207
  • 收稿日期:2022-04-26 录用日期:2022-06-19 发布日期:2022-06-27
  • 通讯作者: 钟澄 E-mail:cheng.zhong@tju.edu.cn
  • 基金资助:
    国家自然科学基金(52125404);国家自然科学基金(51722403);天津市自然科学基金(18JCJQJC46500);广东省自然科学基金(U1601216);国家“万人计划”青年拔尖人才项目和天津市“131”创新型人才培养工程资助项目

Spontaneous Reduction and Adsorption of K3[Fe(CN)6] on Zn Anodes in Alkaline Electrolytes: Enabling a Long-Life Zn-Ni Battery

Yuanhao Shen1, Qingyu Wang1, Jie Liu1, Cheng Zhong1,2,*(), Wenbin Hu1,2   

  1. 1 Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China
    2 Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Fuzhou 350207, China
  • Received:2022-04-26 Accepted:2022-06-19 Published:2022-06-27
  • Contact: Cheng Zhong E-mail:cheng.zhong@tju.edu.cn
  • About author:Cheng Zhong, Email: cheng.zhong@tju.edu.cn; Tel.: +86-22-85356661
  • Supported by:
    the National Natural Science Foundation of China(52125404);the National Natural Science Foundation of China(51722403);the Tianjin Natural Science Foundation(18JCJQJC46500);the Natural Science Foundation of Guangdong Province(U1601216);the National Youth Talent Support Program, and the "131" First Level Innovative Talents Training Project in Tianjin

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摘要：

采用K3[Fe(CN)6]作为锌镍电池的电解液添加剂，克服了锌阳极的变形。此外，通过一系列实验设计和表征，探索了电解液中金属锌与K3[Fe(CN)6]的反应机理。通过XRD (X-ray diffraction)和XPS (X-ray photo-electron spectroscopy)测试，我们发现金属锌在KOH水溶液中能够与K3[Fe(CN)6]反应，将[Fe(CN)6]3–还原为[Fe(CN)6]4−。添加K3[Fe(CN)6]的锌镍电池实现了更长的循环寿命，比不添加K3[Fe(CN)6]的锌镍电池长3倍以上。在相同循环次数下，改性电解质中锌阳极循环不仅形状变化较小，而且没有出现“死”锌现象，电极添加剂和粘结剂也没有发生偏析。此外，不同于一般的有机添加剂，K3[Fe(CN)6]的加入不仅不会增大电极的极化，还能够提高锌镍电池的放电容量和倍率性能。因此，考虑到这一改性策略有着较高的可行性和较低的成本，K3[Fe(CN)6]添加剂在锌镍电池的实际应用中具有极大的推广潜力。

关键词: 锌镍电池, K3[Fe(CN)6], 电解液添加剂, K4[Fe(CN)6], 变形

Abstract:

In view of the continuously worsening environmental problems, fossil fuels will not be able to support the development of human life in the future. Hence, it is of great importance to work on the efficient utilization of cleaner energy resources. In this case, cheap, reliable, and eco-friendly grid-scale energy storage systems can play a key role in optimizing our energy usage. When compared with lithium-ion and lead-acid batteries, the excellent safety, environmental benignity, and low toxicity of aqueous Zn-based batteries make them competitive in the context of large-scale energy storage. Among the various Zn-based batteries, due to a high open-circuit voltage and excellent rate performance, Zn-Ni batteries have great potential in practical applications. Nevertheless, the intrinsic obstacles associated with the use of Zn anodes in alkaline electrolytes, such as dendrite, shape change, passivation, and corrosion, limit their commercial application. Hence, we have focused our current efforts on inhibiting the corrosion and dissolution of Zn species. Based on a previous study from our research group, the failure of the Zn-Ni battery was caused by the shape change of the Zn anode, which stemmed from the dissolution of Zn and uneven current distribution on the anode. Therefore, for the current study, we selected K3[Fe(CN)6] as an electrolyte additive that would help minimize the corrosion and dissolution of the Zn anode. In the alkaline electrolyte, [Fe(CN)6]3– was reduced to [Fe(CN)6]4– by the metallic Zn present in the Zn-Ni battery. Owing to its low solubility in the electrolyte, K4[Fe(CN)6] adhered to the active Zn anode, thereby inhibiting the aggregation and corrosion of Zn. Ultimately, the shape change of the anode was effectively eliminated, which improved the cycling life of the Zn-Ni battery by more than three times (i.e., from 124 cycles to more than 423 cycles). As for capacity retention, the Zn-Ni battery with the pristine electrolyte only exhibited 40% capacity retention after 85 cycles, while the Zn-Ni battery with the modified electrolyte (i.e., containing K3[Fe(CN)6]) showed 72% capacity retention. Moreover, unlike conventional organic additives that increase electrode polarization, the addition of K3[Fe(CN)6] not only significantly reduced the charge-transfer resistance in a simplified three-electrode system, but also improved the discharge capacity and rate performance of the Zn-Ni battery. Importantly, considering that this strategy was easy to achieve and minimized additional costs, K3[Fe(CN)6], as an electrolyte additive with almost no negative effect, has tremendous potential in commercial Zn-Ni batteries.

Key words: Zn-Ni battery, K3[Fe(CN)6], Electrolyte additive, K4[Fe(CN)6], Shape change