Abstract A facile, one-step, solvent-free ‘dry autoclaving’ synthesis method utilized coffee oil as carbon precursor to obtain micrometer diameter spheroidal carbon particles for lithium ion battery anodes. The spheroidal morphology resulted from the evaporation of liquid oil into liquid/gas phase interphase at elevated temperature (700 °C), followed by solid/gas sublimation interactions during cooling (below 350 °C) in a closed autoclave. A mechanism of spheroidal carbon formation is proposed considering the precursor's composition and chemical interactions during autoclaving. The solid spheroidal carbon exhibits 0.85 g cc−1 tap density and 5 m2 g−1 surface area. Galvanostatic cycling performed at 100 mA g−1 current density delivered a capacity of 290 mAh g−1 after 200 cycles. Battery testing at elevated temperature (50 °C) increased the capacity (350 mAh g−1 after 200 cycles at 100 mA g−1), but with decreased Coulombic efficiency due to faster electrolyte depletion by augmented reaction kinetics. The spherical morphology and carbon structuring are maintained after 250 charge-discharge cycles, indicating the long term stability of the spheroidal carbon as Li-ion anode material.

中文翻译：

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锂离子储存在无定形、固体、球状碳阳极中，由咖啡油干法高压灭菌产生

摘要 一种简便、一步、无溶剂的“干法高压灭菌”合成方法，利用咖啡油作为碳前体，获得用于锂离子电池负极的微米直径球状碳颗粒。球状形态是由于液体油在升高的温度 (700 °C) 下蒸发成液/气相中间相，然后在封闭的高压釜中冷却（低于 350 °C）期间发生固/气升华相互作用。考虑到高压灭菌过程中前体的组成和化学相互作用，提出了球状碳形成的机制。固态球状碳的振实密度为 0.85 g cc-1，表面积为 5 m2 g-1。在 100 mA g-1 电流密度下进行的恒电流循环在 200 次循环后提供了 290 mAh g-1 的容量。在升高的温度 (50 °C) 下进行的电池测试增加了容量（在 100 mA g-1 下循环 200 次后为 350 mAh g-1），但由于反应动力学增加导致电解质消耗更快，库仑效率降低。球形形态和碳结构在 250 次充放电循环后保持不变，表明球形碳作为锂离子负极材料的长期稳定性。