液流电池多孔电极内局部电流密度分布特性和均匀化策略研究

提高液流电池的充放电性能和循环寿命是降低其成本的关键方式和推动其大规模商业化应用的必经之路，因此成为了该领域长期以来不懈追求的目标。然而，液流电池的性能目前受制于局部电流密度在多孔电极内的不均匀分布，造成了电极利用率低、局部过电位高、副反应严重等问题。为了解决这个问题，本项目拟开展对液流电池多孔电极内局部电流密度分布特性和均匀化策略的研究。首先，开发活性物质传输、质子传输、电子传输与电化学反应相耦合的跨尺度模拟程序，阐明制约局部电流密度均匀分布的关键因素；其次，搭建局部电流密度跨尺度在线可视化表征平台，揭示多孔电极内传输性能与电化学性能的相互作用机制；最后，根据对局部电流密度分布特性的理解，发展基于三级梯度结构设计的局部电流密度分布均匀化策略。研究成果将推动高充放电性能和长循环寿命液流电池的开发，促进间歇性可再生能源的利用和分布式能源系统的发展。

Increasing charge-discharge performance and prolonging cycle life are effective to reduce the capital cost of redox flow batteries and enable their widespread adoption for large-scale energy storage, and thus are the long-term target pursued by this research field. However, the performance of redox flow batteries is greatly limited by the non-uniform distribution of local current density in porous electrodes, leading to low electrode utilization, high local overpotentials, and severe side reactions. To address this issue, this project aims to unravel the distribution characteristics of local current density and develop the corresponding homogenization strategies in the porous electrodes of redox flow batteries. Firstly, to elucidate the key factors limiting the homogenization of local current density, multiscale modeling incorporating electroactive species transport, proton transport, charge transport, and electrochemical reactions will be developed. Then, the cross-scale in-situ visualization platform for detecting local current density will be built to reveal the interaction mechanism between transport performance and electrochemical performance in porous electrodes. Finally, based on the local current density distribution characteristics, a triple-level gradient structure design strategy will be developed to promote the uniform distribution of local current density in porous electrodes. Results reported in this project will contribute to the development of redox flow batteries with high charge-discharge performance and long cycle life, which can promote the utilization of renewable energy and the development of distributed energy systems.