Zhang Xuefeng, Li Wenwu, Chen Hongning
Chemical Hybrid Energy Novel Laboratory, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518055, Guangdong, P. R. China.
School of Materials and Energy, Guangdong University of Technology, Guangzhou 51006, China.
ACS Appl Mater Interfaces. 2021 Sep 1;13(34):40552-40561. doi: 10.1021/acsami.1c09590. Epub 2021 Aug 23.
Redox flow batteries (RFBs) have attracted more attention due to their ability of decoupling energy and power, but their low energy density has greatly restricted their applications. Semisolid flow batteries (SSFBs) are a kind of RFBs, but they have high energy density. However, there is a lack of research on semisolid anolytes, and thus the application of SSFBs is still in its infancy. In this work, a low-potential (0.6 V vs Li/Li) CuSiP@C-LiPAA composite is synthesized through a simple high-energy mechanical ball milling and impregnation method based on the CuSiP (CSP) compound; then, it is used to prepare a semisolid anolyte, which is able to achieve a high volumetric capacity of 400 Ah L in static mode and 320 Ah L in intermittent-flow mode. This is the highest volumetric capacity of anolyte so far. The effect of adding binder to a composite is also discussed for the first time, which makes the connection between the composite particles closer and the semisolid suspension more uniform so as to obtain stable electrochemical performance. At the same time, through pairing respectively with two types of catholytes, liquid 10-methylphenothiazine (MPT) and semisolid LiFePO (LFP), a single-cell voltage of 3 V and more than 100 stable cycles with the Coulombic efficiency of 99% have been achieved by CSP-MPT and CSP-LFP full-cell systems. The result fully demonstrates the applicability of the prepared CSP semisolid anolyte. The synthesis method of adding a binder to the composite in this work also provides a direction for optimizing the suspension for other active materials to be applied to SSFBs in the future.
氧化还原液流电池（RFBs）因其能量与功率解耦的能力而备受关注，但其低能量密度极大地限制了它们的应用。半固态液流电池（SSFBs）是RFBs的一种，但具有高能量密度。然而，对半固态阳极电解液的研究较少，因此SSFBs的应用仍处于起步阶段。在这项工作中，基于CuSiP（CSP）化合物，通过简单的高能机械球磨和浸渍法合成了一种低电位（相对于Li/Li为0.6 V）的CuSiP@C-LiPAA复合材料；然后，用其制备半固态阳极电解液，该电解液在静态模式下能够实现400 Ah/L的高体积容量，在间歇流动模式下为320 Ah/L。这是迄今为止阳极电解液的最高体积容量。首次讨论了向复合材料中添加粘结剂的效果，这使得复合材料颗粒之间的连接更紧密，半固态悬浮液更均匀，从而获得稳定的电化学性能。同时，通过分别与两种类型的阴极电解液（液态10-甲基吩噻嗪（MPT）和半固态LiFePO（LFP））配对，CSP-MPT和CSP-LFP全电池系统实现了3 V的单电池电压和100多个稳定循环，库仑效率为99%。结果充分证明了所制备的CSP半固态阳极电解液的适用性。这项工作中向复合材料中添加粘结剂的合成方法也为未来优化其他活性材料应用于SSFBs的悬浮液提供了方向。
