Effects of Cs2CO3 Additive in KOH Electrolyte Used in Ni/MH Batteries

Abstract

Abstract:The effects of Cs 2 CO 3 addition in a KOH-based electrolyte were investigated for applications in nickel/metal hydride batteries. Both MgNi-based and Laves phase-related body-centered cubic solid solution metal hydride alloys were tested as the anode active materials, and sintered β-Ni(OH) 2 was used as the cathode active material. Certain amounts of Cs 2 CO 3 additive in the KOH-based electrolyte improved the electrochemical performances compared with a conventional pure KOH electrolyte. For example, with Laves phase-related body-centered cubic alloys, the addition of Cs 2 CO 3 to the electrolyte improved cycle stability (for all three alloys) and discharge capacity (for the Al-containing alloys); moreover, in the 0.33 M Cs 2 CO 3 + 6.44 M KOH electrolyte, the discharge capacity of Mg 52 Ni 39 Co 3 Mn 6 increased to 132%, degradation decreased to 87%, and high-rate dischargeability stayed the same compared with the conventional 6.77 M KOH electrolyte. The effects of Cs 2 CO 3 on the physical and chemical properties of Mg 52 Ni 39 Co 3 Mn 6 were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, inductively coupled plasma, and electrochemical impedance spectroscopy. The results from these analyses concluded that Cs 2 CO 3 addition changed both the alloy surface and bulk composition. A fluffy layer containing carbon was found covering the metal particle surface after cycling in the Cs 2 CO 3 -containing electrolyte, and was considered to be the main cause of the reduction in capacity degradation during cycling. Also, the Cs 2 CO 3 additive promoted the formations of the C-O and C=O bonds on the alloy surface. The C-O and C=O bonds were believed to be active sites for proton transfer during the electrochemical process, with the C-O bond being the more effective of the two. Both bonds contributed to a higher surface catalytic ability. The addition of 0.33 M Cs 2 CO 3 was deemed optimal in this study.

18650 lityum-iyon ve 6HR61 nikel-metal hidrit tekrar şarj edilebilir pillerinin elektrokimyasal empedans analizi

“…Ni-MH pilleri 1960'lı yıllarda keşfedilmiş olup ticari olarak 1989 yılından bu yana elektrikli aletler, robotlar, vakum temizleyiciler, elektrikli oyuncaklar, kablosuz telefonlar, cep telefonları, acil ışıklandırma sistemleri, dizüstü bilgisayarlar, hesap makineleri, taşınabilir kayıt cihazları, oyuncaklar, fotoğraf ve video ekipmanları, kablosuz fare ve klavyeler, hibrit elektrikli araçlar, endüstriyel enerji depolama ve hafif raylı sistemler gibi pek çok alanda kullanıma sahiptir [9][10][11]. Ni-MH pilleri diğer pil teknolojilerine göre geniş sıcaklık çalışma aralığı, uzun kullanım süresi ve yüksek spesifik güç gibi çok sayıda önemli özelliğe sahiptir.…”

“…Ni-MH pilleri diğer pil teknolojilerine göre geniş sıcaklık çalışma aralığı, uzun kullanım süresi ve yüksek spesifik güç gibi çok sayıda önemli özelliğe sahiptir. Bu özellikler son yıllarda yeniden pek çok araştırmacının ve enerji pazarının yeniden bu piller üzerinde çalışmalar yapmasına neden olmuştur [10]. Ni-MH pilinde pozitif elektrot olarak hidrojen absorplayan metal alaşım (metal hidrit, MH) kullanılırken negatif elektrot olarak deşarj durumunda nikel hidroksite indirgenen nikel oksihidroksit (NiOOH) kullanılmaktadır [12].…”

“…Ayrıca, kullanılan elektrokimyasal empedans spektroskopi tekniği ile geliştirilen modelin, enerji ihtiyacının karşılanması ve gelecekte üretilecek pillerin tasarımı için etkili olabileceği ve büyük bir potansiyele sahip olduğu ortaya konmuştur. 10.17341/gazimmfd.463280 Anahtar Kelimeler: Empedans spektroskopisi, tekrar şarj edilebilir pil, eşdeğer devre, pil performansı, gözenekli elektrot Electrochemical impedance analysis of 18650 lithium-ion and 6HR61 nickel-metal hydride rechargeable batteries Impedance spectroscopy, rechargeable battery, equivalent circuit, battery performance, porous electrode * Sorumlu Yazar/Corresponding Author: umorali@ogu.edu.tr, esalim@ogu.edu.tr / Tel: +90 222 239 3750 / 3652…”

The application of nimh batteries in a light-duty electric vehicle

“…The capacity the BCC-C14 alloy was 30% higher than the classic AB 5 alloy. In the research and development of the new electrolyte, many samples of the modified aqueous KOH were tested [20]. Research has shown that the way to increase energy density is to achieve higher cell voltage; therefore, the focus was on IL fluids (ionic liquid), consisting of only anions and cations and characterised by, among other features, high thermal stability, high ion conductivity and non-flammability.…”

Research in Nickel/Metal Hydride Batteries 2017

“…In 2016, we reported that the reduction of the corrosion nature of the alkaline KOH electrolyte can be accomplished by selection of both adequate combination of alkaline species [22] and salt additives [23]. In this Special Issue, the effects of adding Cs 2 CO 3 salt in the electrolyte was further investigated, and a newly formed surface amorphous oxide was credited for the reduction of surface oxidation of the MgNi-based MH alloy [24]. Another breakthrough was using the ionic liquid to replace the aqueous KOH solution as the electrolyte [8].…”