苯甲酸锂、对苯二甲酸锂及均苯三甲酸锂的电化学性能

Electrochemical Properties of Lithium Salts from Benzoic,Eerephthalic,and Trimesic Acids

采用苯甲酸、对苯二甲酸、均苯三甲酸分别与氢氧化锂进行简单中和反应生成相应的苯甲酸锂、对苯二甲酸锂、均苯三甲酸锂.将这些盐作为有机负极嵌锂材料,研究其电化学性能.结果表明,苯甲酸锂、对苯二甲酸锂、均苯三甲酸锂电极材料在0.1C倍率下首次放电容量分别为250、340、268 mAh/g,50次循环后,其放电容量分别为75、100、60 mAh/g,表明对苯二甲酸锂电极材料循环前后放电容量最高.通过溶解性实验表明对苯二甲酸锂最难溶解在有机电解液中.对苯二甲酸锂能够通过O^-—Li…O^-键作用形成二维"大分子链"的结构,能有效抑制溶解.实验结果显示,对苯二甲酸锂电极材料有望成为锂离子电池有机负极材料.

Three lithium salts were synthesized by a simple one-pot neutralization reaction between Li OH and benzoic acid,terephthalic and benzene-1,3,5-tricarboxylic acids,and the electrochemical properties of the three salts were investigated. The electrochemical test exhibits that lithium benzoate,lithium terephthalate and lithium benzene-1,3,5-tricarboxylic acid salts displayed the initial discharge capacity of 250,340,268 m Ah/g at a current rate of 0.1 C and the discharge specific capacity of 75,100,60 mAh/g after 50 cycles,respectively. The solubility experiment shows that lithium terephthalate is the most insoluble in organic electrolyte. Further,lithium terephthalate can form a two dimensional "macromolecular chain"structure by a O-Li…O-bond,which inhibited greatly the solubility of lithium terephthalate in organic electrolyte. The results indicate that lithium terephthalate is the most promising organic electroactive material for anode of LIBs.