全钒液流电池用双极板材料研究进展

Research of Bipolar Plate Materials Used for Vanadium Redox Flow Battery

双极板是全钒液流电池(VRFB)不可或缺的多功能元件。双极板在全钒液流电池中起着重要的作用,如以串联/并联的方式连接多个单电池,提供从kW到多MW的容量,分离每个电池,防止电极之间的直接接触,为电堆提供结构支撑等,这些功能与燃料电池双极板的功能非常相似。然而,与燃料电池不同的是,VRFB中的双极板会遇到强酸性环境和变化的电压条件,这严重限制了双极板材料的选择。详细介绍了各种类型的双极板材料(金属基、石墨基和碳/聚合物复合基)及其加工方法。还介绍了与双极板材料相关的挑战,如界面腐蚀、界面接触电阻和电解液泄漏等。

Bipolar plate is an indispensable multifunctional component of all-vanadium flow battery(VRFB).Bipolar plates play an important role in all-vanadium flow cells,such as connecting multiple single cells in series/parallel connection,providing capacity from kW to multi-MW,separating each cell,preventing direct contact between electrodes,providing structural support for the reactor,etc.These functions are very similar to those of fuel cell bipolar plates.However,unlike fuel cells,bipolar plates in VRFB encounter highly acidic environments and varying voltage conditions,which severely limit the choice of bipolar plate materials.Due to the strong corrosiveness of metal media,metal becomes the most unsuitable candidate for bipolar plate in VRFB.Various types of bipolar plate materials(metal base,graphite base and carbon/polymer composite base)and their processing methods are introduced in detail.Challenges associated with bipolar plate materials such as interfacial corrosion,interfacial contact resistance,bipolar plate expansion,and electrolyte leakage are also described.