Eckert Martin, Suthar Heena, Drillet Jean-Francois
DECHEMA-Forschungsinstitut, Theodor-Heuss-Allee 25, 60486 Frankfurt am Main, Germany.
Materials (Basel). 2022 Apr 1;15(7):2597. doi: 10.3390/ma15072597.
Carbon xerogels were synthesized using a soft-template route with resorcinol as the carbon source and sodium carbonate as the catalyst. The influence of the resorcinol to catalyst ratio in the range of 500-20,000 on pore structure, graphitic domains, and electronic conductivity of as-prepared carbon xerogels, as well as their performance in an aluminium ion battery (AIB), was investigated. After carbonization steps of the polymers up to 800 °C, all carbon samples exhibited similar specific volumes of micropores (0.7-0.8 cm³ g), while samples obtained from mixtures with R/C ratios lower than 2000 led to carbon xerogels with significantly higher mesopore diameters up to 6 nm. The best results, in terms of specific surface (1000 m² g), average pore size (6 nm) and reversible capacity in AIB cell (28 mAh g @ 0.1 A g), were obtained with a carbon xerogel sample synthetized at a resorcinol to catalyst ratio of R/C = 500 (CXG). Though cyclic voltammograms of carbon xerogel samples did not exhibit any sharp peaks in the applied potential window, the presence of both oxidation and a quite wide reduction peak in CXG cyclic voltammograms indicated pseudocapacitance behaviour induced by diffusion-controlled intercalation/de-intercalation of AlCl ions into/from the carbon xerogel matrix. This was confirmed by shifting of the (002) peak towards lower 2θ angle values in the XRD pattern of the CXG electrode after the charging step in AIB, whereas the contribution of pseudocapacitance, calculated from half-cell measurements, was limited to only 6% of overall capacitance.
采用以间苯二酚为碳源、碳酸钠为催化剂的软模板法合成了碳干凝胶。研究了间苯二酚与催化剂比例在500 - 20000范围内对所制备碳干凝胶的孔结构、石墨化域、电子导电性及其在铝离子电池（AIB）中的性能的影响。在聚合物碳化至800℃后，所有碳样品的微孔比体积相似（0.7 - 0.8 cm³/g），而从R/C比低于2000的混合物中获得的样品导致碳干凝胶的中孔直径显著增大，可达6nm。在间苯二酚与催化剂比例为R/C = 500合成的碳干凝胶样品（CXG）中，获得了比表面积（1000 m²/g）、平均孔径（6nm）和AIB电池可逆容量（在0.1 A/g时为28 mAh/g）方面的最佳结果。尽管碳干凝胶样品的循环伏安图在施加的电位窗口中未显示任何尖锐峰，但CXG循环伏安图中氧化峰和相当宽的还原峰的存在表明，AlCl离子在碳干凝胶基质中扩散控制的嵌入/脱嵌诱导了赝电容行为。这在AIB充电步骤后CXG电极的XRD图谱中（002）峰向较低2θ角值的移动中得到证实，而根据半电池测量计算的赝电容贡献仅占总电容的6%。
