生物炭负载金属硒化物复合材料的储锂性能

通过高温对膨化大米进行炭化处理得到米炭(Puffed Rice Carbon, PRC)，以米炭(作为生物炭)和商业Sn、Se粉为原材料，采用高能球磨法在氩气保护气氛中球磨48 h，制备了SnSe/PRC锂离子电池负极材料.用X射线衍射、扫描电子显微镜(含能谱分析)、恒流充放电测试、循环伏安法和电化学阻抗谱等技术对材料进行结构、形貌表征和电化学性能测试.结果表明:在高能机械力作用下，米炭与Sn、Se相互挤压形成合金/碳复合镶嵌结构，提升了体系的导电性能，缓冲了材料的体积膨胀效应，改善了纯合金相的结构稳定性.在电流密度500 mA/g、电压范围0.01~3.00 V条件下进行充放电循环，SnSe/PRC的首次放电比容量较高(704.00 mAh/g)，经50次充放电循环后比容量稳定保持在608.90 mAh/g.该材料还具有良好的倍率性能，在较大电流密度下容量仍保持稳定，当恢复至初始电流密度时，容量能恢复到原有水平.利用环境友好且易制得的生物炭材料能有效地改善了SnSe的储锂性能，对金属硒化物在锂离子电池方面的应用有很好的参考价值.

The Lithium Storage Performance of Biochar-Loaded Metal Selenide Composite Material

Puffed rice carbon was obtained by carbonizing puffed rice at high temperature. Puffed rice carbon (used as biochar) and commercial Sn and Se powder were used to design SnSe/PRC anodes for lithium ion batteries with a high-energy ball grinding method under inert argon atmosphere with 600 r/m for 48 hours. The structure, morphology and electrochemical property of the materials were characterized with X-ray diffraction, scanning electron microscopy (including energy dispersive spectrometer), galvanostatical cycling tests, cyclic voltammetry and electrochemical impedance spectroscopy. Under the action of high energy mechanical force, puffed rice carbon, Sn and Se powder extruded each other to form an alloy/carbon inlaid structure, which improved the electrical conductivity, buffered the large volume expansion effect and improved the structural stability. When cycled at a current density of 500 mA/g in 0.01~3.00 V, SnSe/PRC presented a high initial discharge capacity of 703.9 mAh/g and retained a stable capacity of 608.9 mAh/g after 50 cycles. It also had a good rate performance. Its capacity remained stable under high current densities. When the initial current density was restored, the capacity returned to the initial level. The research shows that the utilization of this environment-friendly and facile biochar can effectively improve the lithium storage performance of SnSe, which has a good reference value for the application of metal selenide in the lithium ion battery.