Zhang Mo, Guan Jing, Tu Yunchuan, Wang Suheng, Deng Dehui
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
State Key Laboratory of Catalysis, iChEM, Dalian Institute of Chemical Physics, Chinese Academy of Science, Zhongshan Road 457, Dalian 116023, China.
Innovation (Camb). 2021 Jul 15;2(3):100144. doi: 10.1016/j.xinn.2021.100144. eCollection 2021 Aug 28.
Decoupled electrolysis of water is a promising strategy for peak load regulation of electricity. The key to developing this technology is to construct decoupled devices containing stable redox mediators and corresponding efficient catalysts, which remains a considerable challenge. Herein, we designed a high-performance device, using polysulfides as mediators and graphene-encapsulated CoNi as catalysts. It produced H with a low potential of 0.82 V at 100 mA/cm, saving 60.2% more energy than direct water electrolysis. The capacity of H production reached 2.5×10 mAh/cm, which is the highest capacity reported so far. This device exhibited excellent cyclability in 15-day recycle tests, without any decay of performance. The calculation results revealed that the electronic structure of the graphene shell was modulated by the electron transfer from N-dopant and metal core, which significantly facilitated recycle of polysulfides on graphene surfaces. This study provides a promising method for constructing a smart grid by developing efficient decoupled devices.
水的解耦电解是一种很有前景的电力调峰策略。开发这项技术的关键是构建包含稳定氧化还原介质和相应高效催化剂的解耦装置，这仍然是一个巨大的挑战。在此，我们设计了一种高性能装置，使用多硫化物作为介质，石墨烯包裹的钴镍作为催化剂。它在100 mA/cm²的电流密度下以0.82 V的低电位产生氢气，比直接水电解节省60.2%以上的能量。产氢容量达到2.5×10³ mAh/cm²，这是迄今为止报道的最高容量。该装置在15天的循环测试中表现出优异的循环稳定性，性能没有任何衰减。计算结果表明，石墨烯壳层的电子结构通过氮掺杂剂和金属核的电子转移得到调制，这显著促进了多硫化物在石墨烯表面的循环。这项研究为通过开发高效解耦装置构建智能电网提供了一种很有前景的方法。
