Surface-fluorinated graphite anode materials for Li-ion batteries
Surface-fluorinated graphite anode materials for Li-ion batteries
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DOI：
10.1016/j.jfluchem.2005.03.014
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发表时间：
2005-07
影响因子：
1.9
通讯作者：
H. Groult;T. Nakajima;L. Perrigaud;Y. Ohzawa;H. Yashiro;S. Komaba;N. Kumagai
中科院分区：
文献类型：
--
作者：
H. Groult;T. Nakajima;L. Perrigaud;Y. Ohzawa;H. Yashiro;S. Komaba;N. Kumagai
用元素氟在200℃和300℃对石墨粉进行了化学氟化表面改性，这一过程由于部分CC键断裂而导致BET比表面积增加。用二次离子质谱仪进行的表面分析表明，这种氟化处理显著降低了石墨表面的H+O含量。用氟化石墨粉作为锂离子电池的负极，计时电位法测试表明，氟化石墨粉比原石墨粉表现出更好的电化学性能，这主要是由于氟化石墨粉的比表面积增大，可以将更多的锂储存到主体晶格中。此外，在脱氢状态下进行的阻抗测量表明，电池总电阻显著降低，即电荷转移电阻和与固体电解质界面(SEI)层相关的电阻都减小。
Surface modification of graphite powder has been performed by chemical fluorination using elemental fluorine at 200°C and 300°C. This process leads to an increase of the BET surface area due to partial CC bond breaking. Surface analyses performed by secondary ions mass spectrometry have shown that the H+O content at the surface of graphite is significantly decreased by this fluorination treatment. Fluorinated graphite powders have been tested as negative electrodes in Li-ion battery, chronopotentiometry measurements have shown that the fluorinated graphite exhibits better electrochemical performances than raw graphite powder notably due to an increase of the surface area which allows the storage of a higher amount of lithium into the host lattice. In addition, impedance measurements performed in a delithiated state have shown a significant decrease of the total cell resistance, i.e. a decrease of both the charge transfer resistance and the resistance related to the solid electrolyte interface (SEI) layer.