热电池用改性LiB合金的物理与电化学性能研究

Study on physical and electrochemical properties of modified LiB alloy for thermal battery

对LiB合金改性前后的物理特性和电化学性能进行了研究,结果表明:在LiB合金中掺杂的离子导电剂越多,密度越大,活性Li含量越低;LiB合金改性后的物相结构主要由Li7B6、活性Li和离子导电剂构成,离子导电剂的加入可以提高LiB中Li7B6骨架的致密性,并且致密性随离子导电剂的增加而增加;LiB合金的内阻随着离子导电剂掺杂量的增加而降低,当掺杂的离子导电剂的质量分数为10%时,LiB合金表现出了良好的电化学性能,并且能够有效解决LiB合金电池在低温、大电流密度放电前期出现的电压凹峰问题.同时,掺杂离子导电剂的LiB合金具有良好的安全性能.

The physical and electrochemical properties of LiB alloy before and after modification were studied.The results show that the more ionic conductive agents doped in LiB alloy,the higher the density,the lower the active Li content.The phase structure of LiB alloy after modification is mainly Li7B6,active Li and ionic conductive agent.The addition of ionic conductive agent can improve the compactness of Li7B6 skeleton in LiB,and the compactness increases with the increase of ionic conductive agent.The internal resistance of LiB alloy decreases with the increase of the doping amount of ionic conductive agent,the LiB alloy shows good electrochemical performance when the mass fraction of the doped ionic conductive agent is 10%,and the voltage concave peak problem of LiB alloy battery can be effectively solved in the early discharge stage at low temperature and high current density.The LiB alloy doped with ion conductive agent has good safety performance.