天津大学杨全红团队报道了不可移动的聚阴离子骨架实现用于紧凑的能量存储，具有前所未有的面积电容的900 μm厚电极。相关研究成果发表在2024年6月14日出版的《国家科学评论》。

加厚电极对于最大化活性成分的比例并因此提高实际储能电池的能量密度至关重要。然而，由于厚电极的离子传输电阻显著增加，电极厚度和电化学性能之间的权衡仍然存在。

该文中，研究人员提出通过在电极孔内建立固定的聚阴离子骨架，来加速离子通过厚而致密的电极的传输。作为概念的证明，原位合成了作为超级电容器骨架的凝胶聚丙烯酸电解质。在充电和放电过程中，质子在RCOO位点之间快速跳跃进行定向传输，从根本上减少了由浓度梯度引起的电极扭曲和极化的影响。

因此，即使在900μm厚的致密电极的情况下，每单位厚度也能获得几乎恒定的离子传输电阻，导致在1 mA cm^-2时14.85 F cm^-2和在100 mA cm^-2时4.26 F cm^-2的前所未有的面电容。

该项研究为加速离子通过厚而致密的电极传输提供了一种有效的方法，表明了在包括但不限于超级电容器在内的储能设备中，实现高能量密度的重要解决方案。

附：英文原文

Title: Immobile polyanionic backbone enables a 900-μm-thick electrode for compact energy storage with unprecedented areal capacitance

Author: Li, Haoran, Wu, Zhitan, Liu, Xiaochen, Lu, Haotian, Zhang, Weichao, Li, Fangbing, Yu, Hongyuan, Yu, Jinyang, Zhang, Boya, Xiong, Zhenxin, Tao, Ying, Yang, Quan-Hong

Issue&Volume: 2024-06-14

Abstract: Thickening electrodes is critical for maximizing the proportion of active components and thus improving the energy density of practical energy storage cells. Nevertheless, trade-offs between electrode thickness and electrochemical performance persist because of the considerably increased ion transport resistance of thick electrodes. Herein, we propose accelerating ion transport through thick and dense electrodes by establishing an immobile polyanionic backbone within the electrode pores; and as a proof of concept, gel polyacrylic electrolytes as such a backbone are in situ synthesized for supercapacitor. During charge and discharge, protons rapidly hop among RCOO sites for oriented transport, fundamentally reducing the effects of electrode tortuosity and polarization resulting from concentration gradients. Consequently, nearly constant ion transport resistance per unit thickness is achieved, even in the case of a 900-μm-thick dense electrode, leading to unprecedented areal capacitances of 14.85 F cm2 at 1 mA cm2 and 4.26 F cm2 at 100 mA cm2. This study provides an efficient method for accelerating ion transport through thick and dense electrodes, indicating a significant solution for achieving high energy density in energy storage devices, including but not limited to supercapacitors.

DOI: 10.1093/nsr/nwae207

Source: https://dx.doi.org/10.1093/nsr/nwae207