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.