Choi Seung Ho, Baucom Jesse, Li Xinru, Shen Li, Seong Young-Hoon, Han In Sub, Choi Yun Ju, Ko You Na, Kim Hae Jin, Lu Yunfeng
Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA.
Energy Materials Laboratory, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon, Republic of Korea.
J Colloid Interface Sci. 2020 Oct 1;577:48-53. doi: 10.1016/j.jcis.2020.05.051. Epub 2020 May 18.
Porous carbon materials are promising candidates for anode materials in rechargeable potassium-ion batteries. However, their high surface area and low crystallinity usually cause side reactions with electrolytes and slanted charge/discharge profiles. Herein, we report the synthesis of porous carbon microspheres with highly graphitized structure and enhanced potassium-ion storage properties. The prepared carbon microspheres exhibit a low working potential of ~0.2 V, high Coulombic efficiency, and a stable reversible capacity of 292.0 mAh/g after 100 cycles, which is significantly higher than that of commercial graphite (137.5 mAh/g after 100 cycles). These desirable performances are attributed to the high crystallinity of carbon and its porous structure, which provide active sites for potassium-ion storage and alleviate the stress caused by the large volume change during the insertion and extraction of potassium ions.
多孔碳材料是可充电钾离子电池阳极材料的理想候选者。然而，它们的高表面积和低结晶度通常会导致与电解质发生副反应以及充放电曲线倾斜。在此，我们报道了具有高度石墨化结构和增强的钾离子存储性能的多孔碳微球的合成。所制备的碳微球表现出约0.2 V的低工作电位、高库仑效率，并且在100次循环后具有292.0 mAh/g的稳定可逆容量，这明显高于商业石墨（100次循环后为137.5 mAh/g）。这些理想的性能归因于碳的高结晶度及其多孔结构，它们为钾离子存储提供了活性位点，并减轻了钾离子嵌入和脱出过程中因体积大幅变化而引起的应力。
