不同单价电解质水溶液对逆电渗析电堆工作特性的影响

以5种工质盐溶液作为逆电渗析堆（RED）的工作溶液，分别在两种浓度（mol/L）比（3/0.05、5/0.05）下，分析逆电渗析堆主要工作特性参数：开路电压、电堆欧姆内阻以及功率密度。实验结果表明：电导率高的电解质溶液为工质时，电堆内阻降低，实验中以浓度比5/0.05溴化铵溶液为工质的电堆具有最低的欧姆内阻（2.80Ω），同时电堆开路电压也最低（1.355V）。因为过高的溶液浓度梯度降低了离子交换膜的离子选择透过性。浓度比5/0.05乙酸钾溶液为工质的电堆具有高的开路电压，达到1.929V，比氯化锂溶液高6.9%，但其电堆内阻比氯化锂溶液高17%，以氯化锂溶液为工质的电堆输出的最大功率密度达到2.217W/m²。以乙酸钠溶液为工质开路电压比乙酸钾稍低，但其内阻过高，使得输出的最大功率密度最小。

Influences of different monovalent electrolyte aqueous solution on the performance characteristics of reverse electrodialysis stack

The present work experimentally investigates the use of five pure salt solutions as working solution in a lab-scale reverse electrodialysis (RED) stack. The main performance parameters of RED stack were analyzed in terms of open circuit voltage (OCV), stack ohm-resistance and power density. Effect of two concentration gradients (3/0.05 and 5/0.05) was investigated. Results show that the electrolyte solution with high electric conductivity is good to reduce stack ohm-resistance. The experimental lowest stack resistance of 2.8Ω was measured when using NH₄Br solution at concentration of 5/0.05, meanwhile, the experimental lowest OCV reached at 1.355V. Because the permselectivity of ion-exchange membranes is weakened at high concentration. The experimental highest OCV of 1.929V was measured when using KAc solution at concentration of 5/0.05, which is about 9% higher than the OCV in LiCl at the same concentration. Due to 17% lower resistance, the latter achieved the maximum power density of 2.217W/m². The OCV in NaAc is slightly lower than that in KAc, but the latter internal resistance is too high, which makes the latter maximum power density minimum.