Influence of cointercalated HF on the electrochemical behavior of highly fluorinated graphite
Influence of cointercalated HF on the electrochemical behavior of highly fluorinated graphite
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DOI：
10.1016/j.jpowsour.2004.05.042
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发表时间：
2004-10
影响因子：
9.2
通讯作者：
T. Nakajima;Vinay Gupta;Y. Ohzawa;H. Groult;Z. Mazej;B. Žemva
中科院分区：
文献类型：
--
作者：
T. Nakajima;Vinay Gupta;Y. Ohzawa;H. Groult;Z. Mazej;B. Žemva
以高氧化态过渡金属复合氟化物（K2 PdF 6、K2 MnF 6、K2 NiF 6或KAgF 4）和单质氟为原料，在无水液体HF（aHF）中，于室温下加压（（5.9-11.8）× 105 Pa）制备了高氟化石墨。氟化石墨样品的组成范围为C1.1F至C1.9F，含有少量HF。红外吸收光谱显示，CxF的阶段1相包含几个不同的相，具有平面（sp2）和褶皱（sp3）石墨烯层。电化学放电的氟化石墨表明，放电电位和放电容量的分布取决于共插层HF的量。HF和HF 2 δ−含量较少的CxF样品具有相对平坦的放电电位和较大的放电容量。在1 mol/dm ~ 3LiClO_4-碳酸亚丙酯溶液中，25 ℃下放电容量可达500- 600 mAh/g。由阻抗测量的Li+离子在中间放电产物中的化学扩散系数为（4.4-13）×10− 12 cm 2/s。
Highly fluorinated graphite was prepared at room temperature using high oxidation state transition metal complex fluoride (K2PdF6, K2MnF6, K2NiF6or KAgF4) and elemental fluorine under pressure ((5.9–11.8) ×105Pa) in anhydrous liquid HF (aHF). The composition of the fluorinated graphite samples ranged from C1.1F to C1.9F containing small amounts of HF. IR absorption spectra revealed that stage 1 phase of CxF contained several different phases with planar (sp2) and puckered (sp3) graphene layers. Electrochemical discharge of the fluorinated graphite showed that profile of discharge potential and discharge capacity varied depending on the amount of cointercalated HF. The CxF samples with less amounts of HF and HF2δ−had relatively flat discharge potentials and large discharge capacities. The discharge capacity reached 500–600mAh/g in 1mol/dm3LiClO4–propylene carbonate solution at 25°C. Chemical diffusion coefficients of Li+ion in the intermediate discharge products were (4.4–13) ×10−12cm2/s from impedance measurement.