Zhou Shuang, Meng Xinyu, Chen Yining, Li Jianwen, Lin Shangyong, Han Chao, Ji Xiaobo, Chang Zhi, Pan Anqiang
Department of Materials Physics and Chemistry, School of Materials Science and Engineering, Central South University, 410083, Changsha, Hunan, China.
School of Mineral Processing and Bioengineering, Central South University, 410083, Changsha, Hunan, China.
Angew Chem Int Ed Engl. 2024 Jun 10;63(24):e202403050. doi: 10.1002/anie.202403050. Epub 2024 May 3.
Unstable Zn interface with serious detrimental parasitic side-reactions and uncontrollable Zn dendrites severely plagues the practical application of aqueous zinc-ion batteries. The interface stability was closely related to the electrolyte configuration and Zn depositional behavior. In this work, a unique Zn-ion anchoring strategy is originally proposed to manipulate the coordination structure of solvated Zn-ions and guide the Zn-ion depositional behavior. Specifically, the amphoteric charged ion additives (denoted as DM), which act as zinc-ion anchors, can tightly absorb on the Zn surface to guide the uniform zinc-ion distribution by using its positively charged -NR groups. While the negatively charged -SO groups of DM on the other hand, reduces the active water molecules within solvation sheaths of Zn-ions. Benefiting from the special synergistic effect, Zn metal exhibits highly ordered and compact (002) Zn deposition and negligible side-reactions. As a result, the advanced Zn||Zn symmetric cell delivers extraordinarily 7000 hours long lifespan (0.25 mA cm, 0.25 mAh cm). Additionally, based on this strategy, the NHVO||Zn pouch-cell with low negative/positive capacity ratio (N/P ratio=2.98) maintains 80.4 % capacity retention for 180 cycles. A more practical 4 cm*4 cm sized pouch-cell could be steadily cycled in a high output capacity of 37.0 mAh over 50 cycles.
不稳定的锌界面伴随着严重有害的寄生副反应和不可控的锌枝晶，严重困扰着水系锌离子电池的实际应用。界面稳定性与电解质构型和锌沉积行为密切相关。在这项工作中，首次提出了一种独特的锌离子锚定策略，以操纵溶剂化锌离子的配位结构并引导锌离子的沉积行为。具体而言，两性带电离子添加剂（表示为DM）作为锌离子锚，可以通过其带正电的-NR基团紧密吸附在锌表面，以引导锌离子均匀分布。另一方面，DM带负电的-SO基团减少了锌离子溶剂化鞘层内的活性水分子。受益于这种特殊的协同效应，锌金属呈现出高度有序且致密的（002）锌沉积，副反应可忽略不计。结果，先进的锌||锌对称电池具有长达7000小时的超长寿命（0.25 mA cm，0.25 mAh cm））。此外，基于该策略，负/正容量比低（N/P比=2.98） 的NHVO||Zn软包电池在180次循环中保持80.4%的容量保持率。一个更实用的4 cm*4 cm尺寸的软包电池可以在37.0 mAh的高输出容量下稳定循环50次。
