利用有机杂化前驱体制备锗碳复合负极材料

Preparation of Ge/C composite anode materials by hybrid Germanium oxide precursor

采用硼氢化钠液相还原法合成了一种锗氧化物GeO_(x)与间苯二甲胺的新型有机杂化前驱体,经过热处理后得到锗碳原位复合的负极材料。对所制复合负极材料的结构和微观形貌进行了分析表征,测试了其电化学性能。研究结果表明:所制前驱体中间苯二甲胺与锗氧化物通过氢键等结合,具有典型的有机-无机杂化结构,热处理后原位形成了丰富的锗碳复合界面,有效缓冲了锗负极材料充放电过程中剧烈体积变化,显著提升了锗基负极材料的可逆容量、倍率性能以及循环稳定性。

M-xylylenediamine germanium oxide(MXDA-GeO_(x))hybrid precursor was synthesized by sodium borohydride aqueous reduction.The Ge/C composite anode material was obtained by annealing of the hybrid precursor at Ar/H_(2) atmosphere.The structure and morphology of the prepared composite anode material were characterized and the electrochemical performance was investigated.The results indicate that the precursor has typical organic-inorganic hybrid structure,in which M-xylylenediamine and germanium oxide are combined by hydrogen binds,and the Ge/C composite interface forms in situ after annealing,thereby effectively relieving the large volume change of germanium during Li-Ge alloy/dealloy processes.Comparing with pure germanium anodes,the obtained composite anode materials show higher capacity and better rate performance and cycling stability.