可充熔盐Fe-空气电池阴极设计及性能研究
发布时间：2018-10-10 13:42
【摘要】：可充熔盐Fe-空气电池,具有能量密度高、成本低、安全和环境友好等特点,有望成为新一代的储能电池。本文设计新型结构的空气阴极,通过降低运行温度、向电解质中添加BaCO_3、优化电解质组成方法延长空气阴极寿命。采用XRD、FE-SEM、EDS及电化学分析测试方法,探索新型结构空气阴极充放电循环性能。研究结果表明,翅片空气阴极具有较大的表面积,翅片之间具有一定间距,不会被电解液 淹死‖,可以充分与空气接触;电极的平板端与电解质液面接触,电解液通过润湿作用在翅片上形成电解质薄液膜,在翅片上形成氧气-电解质-催化剂(气-液-固)三相界面,循环伏安结果表明,翅片阴极具有较好的ORR氧气还原活性,提高了ORR动力学。采用XRD和SEM表征表明,阴极翅片上的原位形成了氧化镍和锂化氧化镍催化剂,催化剂颗粒较均匀。改进后的电池在500℃下稳定运行80个充放电循环,平均充电点烟为1.20V。平均放点电压为1.04V,最高电流效率为93.4%。空气印记在高温熔盐电解质中的腐蚀是电池失效的主要因素。采用降低电池运行温度的方法,在一定程度上减轻了空气阴极的腐蚀,但是降低运行温度导致电池充电和放电极化,充电电压升高,电流效率也相应下降。向电解质中加入一定量的BaCO_3可以减轻阴极腐蚀,电池稳定运行了110多个充放电循环,电池寿命提高了近38%。分别以Li_2SO_4和Li_(0.87)Na_(0.63)K_(0.50)CO_3替代KCl-LiCl-LiOH电解质中的LiCl,研究表明,电解质中LiCl是造成阴极腐蚀的主要因素。KCl-Li_2SO_4-LiOH体系虽然阴极腐蚀减轻,但是电池性能衰减明显,用Li_(0.87)Na_(0.63)K_(0.50)CO_3替代LiCl后,不仅阴极腐蚀问题得到解决,而且电池性能也十分理想。熔融KCl-Li_(0.87)Na_(0.63)K_(0.50)CO_3-LiOH电解质体系下空气电池,在500℃下充放电运行850个循环,库伦效率最高可达98.6%,电压效率最高可达85.9%,为可充电熔盐Fe-空气电池的进一步研究奠定了基础。
[Abstract]:Rechargeable molten salt Fe- air battery is expected to be a new generation of energy storage battery due to its high energy density, low cost, safety and environmental friendliness. A new type of air cathode is designed in this paper. By lowering the operating temperature and adding BaCO_3, to the electrolyte to optimize the electrolyte composition, the life of the air cathode can be prolonged. XRD,FE-SEM,EDS and electrochemical analysis were used to explore the performance of new structure air cathode charge-discharge cycle. The results show that the finned air cathode has a large surface area and a certain distance between the fins, so it will not be drowned by the electrolyte, so it can fully contact with the air, and the plate end of the electrode is in contact with the electrolyte liquid surface. The electrolyte formed thin electrolyte film on the fin by wetting and the three-phase interface of oxygen electrolyte-catalyst (gas-liquid-solid) was formed on the fin. The cyclic voltammetry results showed that the fin cathode had good oxygen reduction activity of ORR. The kinetics of ORR is improved. The results of XRD and SEM showed that nickel oxide and lithium nickel oxide catalysts were formed in situ on the cathode fin, and the catalyst particles were uniform. The improved battery operates 80 charging and discharging cycles stably at 500 鈩，
本文编号：2261999
[Abstract]:Rechargeable molten salt Fe- air battery is expected to be a new generation of energy storage battery due to its high energy density, low cost, safety and environmental friendliness. A new type of air cathode is designed in this paper. By lowering the operating temperature and adding BaCO_3, to the electrolyte to optimize the electrolyte composition, the life of the air cathode can be prolonged. XRD,FE-SEM,EDS and electrochemical analysis were used to explore the performance of new structure air cathode charge-discharge cycle. The results show that the finned air cathode has a large surface area and a certain distance between the fins, so it will not be drowned by the electrolyte, so it can fully contact with the air, and the plate end of the electrode is in contact with the electrolyte liquid surface. The electrolyte formed thin electrolyte film on the fin by wetting and the three-phase interface of oxygen electrolyte-catalyst (gas-liquid-solid) was formed on the fin. The cyclic voltammetry results showed that the fin cathode had good oxygen reduction activity of ORR. The kinetics of ORR is improved. The results of XRD and SEM showed that nickel oxide and lithium nickel oxide catalysts were formed in situ on the cathode fin, and the catalyst particles were uniform. The improved battery operates 80 charging and discharging cycles stably at 500 鈩，
本文编号：2261999
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