Park Jun Heuk, Kwak Myung-Jun, Hwang Chihyun, Kang Kyeong-Nam, Liu Nian, Jang Ji-Hyun, Grzybowski Bartosz A
Center for Soft and Living Matter, Institute for Basic Science, UNIST-gil 50, Ulsan, 44919, South Korea.
Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan, 44919, South Korea.
Adv Mater. 2021 Aug;33(34):e2101726. doi: 10.1002/adma.202101726. Epub 2021 Jul 19.
Despite their safety, nontoxicity, and cost-effectiveness, zinc aqueous batteries still suffer from limited rechargeability and poor cycle life, largely due to spontaneous surface corrosion and formation of large Zn dendrites by irregular and uneven plating and stripping. In this work, these untoward effects are minimized by covering Zn electrodes with ultrathin layers of covalent organic frameworks, COFs. These nanoporous and mechanically flexible films form by self-assembly-via the straightforward and scalable dip-coating technique-and permit efficient mass and charge transport while suppressing surface corrosion and growth of large Zn dendrites. The batteries demonstrated have excellent capacity retention and stable polarization voltage for over 420 h of cycling at 1 mA cm . The COF films essential for these improvements can be readily deposited over large areas and curvilinear supports, enabling, for example, foldable wire-type batteries.
尽管锌水系电池具有安全性、无毒且成本效益高的特点，但仍存在可充电性有限和循环寿命短的问题，这主要是由于自发的表面腐蚀以及不规则和不均匀的电镀与剥离形成了大量锌枝晶。在这项工作中，通过用超薄的共价有机框架（COF）层覆盖锌电极，可将这些不良影响降至最低。这些纳米多孔且具有机械柔韧性的薄膜通过自组装——采用直接且可扩展的浸涂技术——形成，并在抑制表面腐蚀和大尺寸锌枝晶生长的同时，实现高效的质量和电荷传输。所展示的电池在1 mA cm² 的电流密度下循环超过420小时，具有出色的容量保持率和稳定的极化电压。对于这些改进至关重要的COF薄膜可以很容易地沉积在大面积和曲线形支撑物上，例如可实现可折叠的线型电池。
