El Kharbachi Abdelouahab, Uesato Hiroki, Kawai Hironori, Wenner Sigurd, Miyaoka Hiroki, Sørby Magnus H, Fjellvåg Helmer, Ichikawa Takayuki, Hauback Bjørn C
Institute for Energy Technology P. O. Box 40, NO-2027 Kjeller Norway
Institute for Advanced Materials Research, Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima 739-8530 Japan.
RSC Adv. 2018 Jun 27;8(41):23468-23474. doi: 10.1039/c8ra03340d. eCollection 2018 Jun 21.
Several studies have demonstrated that MgH is a promising conversion-type anode toward Li. A major obstacle is the reversible capacity during cycling. Electrochemical co-existence of a mixed metal hydride-oxide conversion type anode is demonstrated for lithium ion batteries using a solid-state electrolyte. 75MgH·25CoO anodes are obtained from optimized mixing conditions avoiding reactions occurring during high-energy ball-milling. Electrochemical tests are carried out to investigate the cycling capability and reversibility of the on-going conversion reactions. The cycling led to formation of a single-plateau nanocomposite electrode with higher reversibility yield, lowered discharge-charge hysteresis and mitigated kinetic effect at high C-rate compared to MgH anodes. It is believed that reduced diffusion pathways and less polarized electrodes are the origin of the improved properties. The designed composite-electrode shows good preservation and suitability with LiBH solid electrolyte as revealed from electron microscopy analyses and X-ray photoelectron spectroscopy.
多项研究表明，氢化镁是一种很有前景的锂转换型负极材料。一个主要障碍是循环过程中的可逆容量。使用固态电解质的锂离子电池证明了混合金属氢化物-氧化物转换型负极的电化学共存。通过优化混合条件获得了75MgH·25CoO负极，避免了高能球磨过程中发生的反应。进行电化学测试以研究正在进行的转换反应的循环能力和可逆性。与氢化镁负极相比，循环导致形成具有更高可逆产率、更低充放电滞后和在高C倍率下减轻动力学效应的单平台纳米复合电极。据信，扩散路径的减少和电极极化的降低是性能改善的原因。电子显微镜分析和X射线光电子能谱显示，所设计的复合电极与LiBH固体电解质具有良好的相容性和适用性。
