Suppression of current-induced membrane discharge of bipolar membranes by regulating ion crossover transport  

作　　者：Tingting Yu Haolan Tao Jingkun Li Cheng Lian Honglai Liu 

机构地区：[1]State Key Laboratory of Chemical Engineering,Shanghai Engineering Research Center of Hierarchical Nanomaterials,School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China [2]School of Chemistry and Molecular Engineering,East China University of Science and Technology,Shanghai 200237,China

出　　处：《Journal of Energy Chemistry》2024年第9期387-395,共9页能源化学（英文版）

基　　金：sponsored by the National Key R&D Program of China(2022YFB4602101);the Fundamental Research Funds for the Central Universities(2022ZFJH004 and 2024SMECP05);the National Natural Science Foundation of China(22278127 and 22378112);the Shanghai Pilot Program for Basic Research(22T01400100-18);the Postdoctoral Fellowship Program of CPSF(GZC20230801)。

摘　　要：Bipolar membranes(BPMs)exhibit the unique capability to regulate the operating environment of electrochemical system through the water dissociation-combination processes.However,the industrial utilization of BPMs is limited by instability and serious energy consumption.The current-induced membrane discharge(CIMD)at high-current conditions has a negative influence on the performance of anion-exchange membranes,but the underlying ion transport mechanisms in the BPMs remain unclear.Here,the CIMD-coupled Poisson-Nernst-Planck(PNP)equations are used to explore the ion transport mechanisms in the BPMs for both reverse bias and forward bias at neutral and acid-base conditions.It is demonstrated that the CIMD effect in the reverse-bias mode can be suppressed by enhancing the diffusive transport of salt counter-ions(Na^(+)and Cl^(−))into the BPMs,and that in the forward-bias mode with acid-base electrolytes can be suppressed by matching the transport rate of water counter-ions(H_(3)O^(+)and OH^(−)).Suppressing the CIMD can promote the water dissociation in the reverse-bias mode,as well as overcome the plateau of limiting current density and reduce the interfacial blockage of salt co-ions(Cl^(−))in the anion-exchange layer in the forward-bias mode with acid-base electrolytes.Our work highlights the importance of regulating ion crossover transport on improving the performance of BPMs.

关 键 词：Bipolar membranes Current-induced membrane discharge Salt ion crossover Diffusion-migration-reaction process 

分 类 号：O646[理学—物理化学]