Abstract:

The thermally regenerative ammonia-based battery (TRAB) exhibits unique advantages and good application prospects in copper-containing electroplating wastewater treatment and recycling. It can remove copper ions while generating electricity from low-temperature waste heat. As one of the critical operating parameters, the load affects the electrochemical reaction rate, the performance of electricity generation and the removal effect of Cu²⁺. In addition, the presence of ammonia permeation significantly affects the removal effect of copper ions. In this paper the TRAB battery was discharged in batches under different loads to investigate the effect of loading on the electrical production and removal rate of Cu²⁺. The reactions of the cathode under different ammonia concentrations were explored using cyclic voltammetry. After discharge, thermal regeneration was carried out to investigate the effects of different regeneration temperatures on the thermal regeneration process, battery power and Cu²⁺ removal rate. The results indicated that a lower load could result in a higher total charge and shorter processing time. In addition, it can improve the coulomb efficiency of the cathode by slowing down the ammonia crossover and reducing the occurrence of side reactions. Therefore, higher removal rates of copper ions were obtained under low load. When the load was 1Ω, a higher power yield (350C) was obtained, the treatment time was shortened to 2.1h and the removal rate of Cu²⁺ reached 80.5%. During the next batch, the thermally regenerative process was important for the battery performance and copper removal rate, which could be enhanced by increasing the regenerative temperature in a certain range.

Key words: thermally regenerative ammonia-based battery, external load, Cu²⁺ removal rate, ammonia permeation, electrochemistry, wastewater

摘要：

热再生氨电池（thermally regenerative ammonia-based battery, TRAB）在利用低温废热产电的同时去除Cu²⁺，在含铜电镀废水的处理及资源回收方面具有独特的优势和良好的应用前景。而作为关键运行参数之一的负载不但影响电化学反应速率和产电性能，而且还会对Cu²⁺去除效果产生影响。此外，氨渗透现象的存在极大地影响了Cu²⁺的去除效果。本文在不同负载条件下对电池进行批次放电，探究负载对电池的产电特性及铜离子去除率的影响，利用循环伏安法探究不同氨浓度条件下阴极发生的反应。对产电后的阳极液进行热再生，探究不同再生温度对热再生过程、电池功率及Cu²⁺去除率的影响。研究结果表明，随着负载的降低（电流增大），电池的产电量得到提升，批次处理所需的时间大幅缩短。并且较小的负载可以有效降低阴极氨渗透量，减弱副反应的发生，从而提升阴极库仑效率，因此获得较高的Cu²⁺去除率。当负载为1Ω时获得了较大的产电量（350C），且处理时间缩短为2.1h，使得废水中Cu²⁺的去除率达到80.5%。热再生过程对下一批次电池性能和阴极Cu²⁺去除有重要影响，一定范围内提升再生温度有利于热再生过程的进行。

关键词: 热再生氨电池, 负载, Cu²⁺去除率, 氨渗透, 电化学, 废水