Department of Química Inorgánica e Ingeniería Química, Instituto de Química Fina y Nanoquímica, University of Córdoba, 14071 Córdoba, Spain.
Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17, Ferrara 44121, Italy.
J Colloid Interface Sci. 2020 Aug 1;573:396-408. doi: 10.1016/j.jcis.2020.03.092. Epub 2020 Mar 25.
Disordered carbons derived from biomass are herein efficiently used as an alternative anode in lithium-ion battery. Carbon precursor obtained from cherry pit is activated by using either KOH or HPO, to increase the specific surface area and enable porosity. Structure, morphology and chemical characteristics of the activated carbons are investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetry (TG), Raman spectroscopy, nitrogen and mercury porosimetry. The electrodes are studied in lithium half-cell by galvanostatic cycling, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The study evidences substantial effect of chemical activation on the carbon morphology, electrode resistance, and electrochemical performance. The materials reveal the typical profile of disordered carbon with initial irreversibility vanishing during cycles. Carbons activated by HPO show higher capacity at the lower C-rates, while those activated by KOH reveal improved reversible capacity at the high currents, with efficiency approaching 100% upon initial cycles, and reversible capacity exceeding 175 mAh g. Therefore, the carbons and LiFePO cathode are combined in lithium-ion cells delivering 160 mAh g at 2.8 V, with a retention exceeding 95% upon 200 cycles at C/3 rate. Hence, the carbons are suggested as environmentally sustainable anode for Li-ion battery.
本文中，我们高效地利用源自生物质的无序碳作为锂离子电池的替代阳极。使用 KOH 或 HPO 对从樱桃核中获得的碳前体进行活化，以增加比表面积并实现多孔性。通过 X 射线衍射 (XRD)、透射电子显微镜 (TEM)、扫描电子显微镜 (SEM)、热重分析 (TG)、拉曼光谱、氮气和汞孔隙率对活化碳的结构、形态和化学特性进行了研究。通过恒电流循环、循环伏安法和电化学阻抗谱 (EIS) 研究了锂半电池中的电极。研究表明，化学活化对碳形态、电极电阻和电化学性能有显著影响。这些材料显示出典型的无序碳形态，初始不可逆性在循环过程中消失。由 HPO 活化的碳在较低的 C 速率下表现出更高的容量，而由 KOH 活化的碳在高电流下显示出改善的可逆容量，初始循环时效率接近 100%，可逆容量超过 175 mAh g。因此，将这些碳与 LiFePO 阴极组合在锂离子电池中，在 2.8 V 时可提供 160 mAh g 的容量，在 C/3 速率下循环 200 次后保留率超过 95%。因此，这些碳被建议作为锂离子电池的环保可持续阳极。
