【摘要】：可充熔鹽Fe-空氣電池,具有能量密度高、成本低、安全和環(huán)境友好等特點(diǎn),有望成為新一代的儲(chǔ)能電池。本文設(shè)計(jì)新型結(jié)構(gòu)的空氣陰極,通過降低運(yùn)行溫度、向電解質(zhì)中添加BaCO_3、優(yōu)化電解質(zhì)組成方法延長空氣陰極壽命。采用XRD、FE-SEM、EDS及電化學(xué)分析測(cè)試方法,探索新型結(jié)構(gòu)空氣陰極充放電循環(huán)性能。研究結(jié)果表明,翅片空氣陰極具有較大的表面積,翅片之間具有一定間距,不會(huì)被電解液 淹死‖,可以充分與空氣接觸;電極的平板端與電解質(zhì)液面接觸,電解液通過潤濕作用在翅片上形成電解質(zhì)薄液膜,在翅片上形成氧氣-電解質(zhì)-催化劑(氣-液-固)三相界面,循環(huán)伏安結(jié)果表明,翅片陰極具有較好的ORR氧氣還原活性,提高了ORR動(dòng)力學(xué)。采用XRD和SEM表征表明,陰極翅片上的原位形成了氧化鎳和鋰化氧化鎳催化劑,催化劑顆粒較均勻。改進(jìn)后的電池在500℃下穩(wěn)定運(yùn)行80個(gè)充放電循環(huán),平均充電點(diǎn)煙為1.20V。平均放點(diǎn)電壓為1.04V,最高電流效率為93.4%�？諝庥∮浽诟邷厝埯}電解質(zhì)中的腐蝕是電池失效的主要因素。采用降低電池運(yùn)行溫度的方法,在一定程度上減輕了空氣陰極的腐蝕,但是降低運(yùn)行溫度導(dǎo)致電池充電和放電極化,充電電壓升高,電流效率也相應(yīng)下降。向電解質(zhì)中加入一定量的BaCO_3可以減輕陰極腐蝕,電池穩(wěn)定運(yùn)行了110多個(gè)充放電循環(huán),電池壽命提高了近38%。分別以Li_2SO_4和Li_(0.87)Na_(0.63)K_(0.50)CO_3替代KCl-LiCl-LiOH電解質(zhì)中的LiCl,研究表明,電解質(zhì)中LiCl是造成陰極腐蝕的主要因素。KCl-Li_2SO_4-LiOH體系雖然陰極腐蝕減輕,但是電池性能衰減明顯,用Li_(0.87)Na_(0.63)K_(0.50)CO_3替代LiCl后,不僅陰極腐蝕問題得到解決,而且電池性能也十分理想。熔融KCl-Li_(0.87)Na_(0.63)K_(0.50)CO_3-LiOH電解質(zhì)體系下空氣電池,在500℃下充放電運(yùn)行850個(gè)循環(huán),庫倫效率最高可達(dá)98.6%,電壓效率最高可達(dá)85.9%,為可充電熔鹽Fe-空氣電池的進(jìn)一步研究奠定了基礎(chǔ)。
[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，

本文編號(hào)：2261999