适用于锂氧电池的高容量碳基电极(英文)

High Capacity Carbon Based Electrodes for Lithium/Oxygen Batteries

以碳酸钠为催化剂，将间苯二酚与甲醛进行缩聚，所生成的气凝胶在800℃的惰性气氛中进行碳化以制备多孔的碳气凝胶。碳的多孔质地由改变凝胶前体中间苯二酚与催化剂的摩尔比来调节，摩尔比的范围为100-500。气凝胶和碳气凝胶的多孔结构以住绝对温度77K下进行的氮气的吸附-解吸附测量结果表征。已经发现，总孔隙度和碳的平均孔径随着凝胶前体的摩尔比的增加而增大。作为一种活性材料，碳气凝胶用于制造合成碳电极。合成碳电极的电化学性能以将其用作锂／氧电池的负极来进行测试。由静电充放电测量发现，随着摩尔比的增加，由碳气凝胶制造的锂／氧电池的比容量由716mA·h·g^-1增加到2077mA·h·g^-1。所得到的最初10次充／放电循环的电压分布图表明，这些碳样品具有出色的循环稳定性。

Porous carbon aerogels are prepared by polycondensation of resorcinol （R） and formaldehyde （F） catalyzed by sodium carbonate （C） followed by carbonization of the resultant aerogels at 800~C in an inert atmosphere. The porous texture of the carbons has been adjusted by the change of the molar ratio of resorcinol to catalyst （R/C） in the gel precursors in the range of 100 to 500. The porous structure of the aerogels and carbon aerogels are characterized by N2 adsorption-desorption measurements at 77 K. It is found that total pore volume and average pore diameter of the carbons increase with increase in the R/C ratio of the gel precursors. The prepared carbon aerogels are used as active materials in fabrication of composite carbon electrodes. The electrochemical performance of the electrodes has been tested by using them as cathodes in a Li/O2 cell. Through the galvanostatic charge/discharge measurements, it is found that with an increase of R/C ratio, the specific capacity of the Li/O2 cell fabricated from the carbon aerogels increases from 716 to 2077 mA.h.g-I. The resulting voltage profiles for the first ten charge/discharge cycles indicate that the carbon samples possess excellent stability on cycling.