Tang Kun, Fu Jimin, Wu Mingzai, Hua Tao, Liu Jun, Song Li, Hu Haibo
School of Materials Science and Engineering, Key Laboratory of Structure and Functional Regulation of Hybrid Materials, Ministry of education, Anhui University, Hefei, 230601, China.
Nanotechnology Center, Institute of Textiles & Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, 999077, Hong Kong.
Small Methods. 2022 Feb;6(2):e2101276. doi: 10.1002/smtd.202101276. Epub 2021 Dec 16.
For the challenging pursuit of high energy efficiency and mechanical tolerance in flexible solid-state Zn-air batteries (FSZABs), a hydrogel electrolyte (HE) consisting of dual-network crosslinked polyacrylic acid-Fe -chitosan (PAA-Fe -CS) polymer host infiltrated with a mixed aqueous electrolyte of NH Cl and ZnCl is developed. The absorbed near-neutral electrolyte renders the HE high ionic conductivity but low corrosiveness to both electrocatalysts and Zn metal anode (ZMA), ensuring more stable Zn-OH-O chemistry compared to that in strong alkaline electrolyte and thus endowing the assembled FSZABs with a landmark cycle life up to 120 h (5 mA cm ). More intriguingly, the CS molecular beams introduced into the PAA hydrogel backbone will precipitate and fold subjecting to the Hofmeister effect when saturated with the near-neutral electrolyte, which can effectively enhance the interfacial adhesion strength of the HE on both air cathode and ZMA, achieving reliable and robust bonding between them. Thus, the FSZABs simultaneously exhibited a superior tolerance to repeated mechanical deformation during operation, allowing more than 360 continuous bending-recovery cycles without any decline in voltage efficiency. The ingenious chemistry and interface synergetic engineering on the crucial HEs provides a rational methodology to realize boosted electrochemical and mechanical durability of FSZABs forward for future practical implementation.
为了在柔性固态锌空气电池（FSZABs）中实现高能效和机械耐受性这一具有挑战性的目标，开发了一种水凝胶电解质（HE），它由双网络交联的聚丙烯酸 - 铁 - 壳聚糖（PAA - Fe - CS）聚合物主体组成，并渗透有NH₄Cl和ZnCl₂的混合水电解质。所吸收的近中性电解质使HE具有高离子电导率，但对电催化剂和锌金属阳极（ZMA）的腐蚀性较低，与强碱性电解质相比，确保了更稳定的Zn - OH - O化学性质，从而使组装的FSZABs具有高达120小时（5 mA cm⁻²）的标志性循环寿命。更有趣的是，引入PAA水凝胶主链的CS分子束在被近中性电解质饱和时会因霍夫迈斯特效应而沉淀和折叠，这可以有效提高HE在空气阴极和ZMA上的界面粘附强度，实现它们之间可靠而牢固的结合。因此，FSZABs在运行过程中同时表现出对重复机械变形的优异耐受性，允许超过360次连续的弯曲 - 恢复循环而电压效率没有任何下降。在关键的HEs上进行的巧妙化学和界面协同工程为实现FSZABs增强的电化学和机械耐久性提供了一种合理的方法，以推动其未来的实际应用。
