苯甲酸锂、对本二酸锂及均苯三甲酸锂的电化学性能

与传统的锂离子电池（LIBs）无机材料相比，有机电极材料因具有理论容量高、可再生、成本低、环境友好等优点已成为LIBs电极材料的热门研究方向. 然而有机材料易溶解在有机电解液中，阻碍有机电极材料的进一步市场化.本文通过含不同数量羧酸的苯甲酸、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，作为有机负极嵌锂材料，并研究不同数量的羧基锂基团对这三种电极材料电化学性能的影响.研究结果显示苯甲酸锂、对苯二甲酸锂、均苯三甲酸锂电极材料在0.1C电流倍率下首次放电容量分别为~250、~340、~268 mAh g-1，50次循环后，其放电容量分别为~75、~100、~60 mAh g-1，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是最难溶解在有机电解液中.对苯二甲酸锂能够通过O-LiO-键作用形成二维大分子链的结构，能有效抑制溶解.从以上实验结果看出，对苯二甲酸锂电极材料是最有希望的LIBs有机负极材料.

Preparation and Electrochemical Properties of Lithium Benzoate with Different Number of -COOLi Groups

Compared with the traditional inorganic materials, organic electroactive materials for lithium ion batteries (LIBs) have many merits including high theoretical capacity, renewability, low cost and environmental benignity, which has become a popular research topic. However, organic materials are easily soluble in organic electrolytes, hindering their applications in LIBs towards market. In this work, three different aromatic acids with different amounts carboxylic acid were synthesized by a simple one-pot neutralization reaction between benzoic acid, terephthalic acid, benzene-1,3,5-tricarboxylic acid and LiOH, respectively, which formed aromatic acid lithium salt as anodes for LIBs, and the effects of the different number COOLi groups on the three electrode materials were investigated. The electrochemical test exhibits that lithium benzoate, lithium terephthalate, lithium benzene-1,3,5-tricarboxylic acid salt displayed the initial discharge capacity of 250, 340, 268 mAh g-1 at a current rate of 0.1 C and the discharge specific capacity of 75, 100, 60 mAh g-1 after 50 cycles. 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 OLiO bond, inhibiting greatly the solubility of lithium terephthalate in organic electrolyte. The above researches indicate that lithium terephthalate is the most promising organic electroactive materials as anodes materials for LIBs.