Yang Qi, Qu Xiaofeng, Cui Huilin, He Xincheng, Shao Yuan, Zhang Yong, Guo Xun, Chen Ao, Chen Ze, Zhang Rong, Kong Duanyang, Shi Zhicong, Liu Jun, Qiu Jieshan, Zhi Chunyi
College of Chemical Engineering, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong SAR, 999077, China.
Angew Chem Int Ed Engl. 2022 Aug 26;61(35):e202206471. doi: 10.1002/anie.202206471. Epub 2022 Jul 21.
Aqueous batteries that use metal anodes exhibit maximum anodic capacity, whereas the energy density is still unsatisfactory partially due to the high redox potential of the metal anode. Current metal anodes are plagued by the dilemma that the redox potential of Zn is not low enough, whereas Al, Mg, and others with excessively low redox potential cannot work properly in aqueous electrolytes. Mn metal with a suitably low redox potential is a promising candidate, which was rarely explored before. Here, we report a rechargeable aqueous Mn-metal battery enabled by a well-designed electrolyte and robust inorganic-organic interfaces. The inorganic Sn-based interface with a bottom-up microstructure was constructed to preliminarily suppress water decomposition. With this bubble-free interface, the organic interface can be formed via an esterification reaction of sucrose triggered by acyl chloride in the electrolyte, generating a dense physical shield that isolates water while permitting Mn diffusion. Hence, a Mn symmetric cell achieves a superior plating/stripping stability for 200 hours, and a Mn||V O battery maintains approximately 100 % capacity after 200 cycles. Moreover, the Mn||V O battery realizes a much higher output voltage than that of the Zn||V O battery, evidencing the possibility of increasing the energy density through using a Mn anode. This work develops a systematic strategy to stabilize a Mn-metal anode for Mn-metal batteries, opening a new door towards enhanced voltage of aqueous batteries.
使用金属阳极的水系电池展现出最大的阳极容量，然而其能量密度仍不尽人意，部分原因在于金属阳极的氧化还原电位较高。当前的金属阳极面临两难困境：锌的氧化还原电位不够低，而铝、镁等氧化还原电位过低的金属在水系电解质中无法正常工作。具有适当低氧化还原电位的锰金属是一个有前景的候选材料，此前很少有人对此进行探索。在此，我们报道了一种通过精心设计的电解质和坚固的无机 - 有机界面实现的可充电水系锰金属电池。构建了具有自下而上微观结构的无机锡基界面，以初步抑制水的分解。借助这个无气泡界面，有机界面可通过电解质中酰氯引发的蔗糖酯化反应形成，产生一个致密的物理屏障，既能隔离水又能允许锰扩散。因此，锰对称电池在200小时内实现了卓越的电镀/脱镀稳定性，并且锰||V O电池在200次循环后保持约100%的容量。此外，锰||V O电池实现了比锌||V O电池高得多的输出电压，证明了使用锰阳极提高能量密度的可能性。这项工作开发了一种系统策略来稳定锰金属电池的锰金属阳极，为提高水系电池的电压开启了一扇新的大门。
