Xiao Pengfei, Wang Zhongming, Long Kecheng, Yang Jixu, Liu Xinsheng, Ling Canhui, Chen Libao, Mei Lin
State Key Laboratory of Powder Metallurgy, Central South University Changsha 410083 P. R. China
National Energy Metal Resources and New Materials Key Laboratory, Central South University Changsha 410083 P. R. China.
RSC Adv. 2024 Apr 24;14(19):13277-13285. doi: 10.1039/d4ra01560f. eCollection 2024 Apr 22.
With the continuous expansion of the lithium-ion battery market, addressing the critical issues of stable cycling and low-temperature operation of lithium-ion batteries (LIBs) has become an urgent necessity. The high anisotropy and poor kinetics of pristine graphite in LIBs contribute to the formation of precipitated lithium dendrites, especially during rapid charging or low-temperature operation. In this study, we design a graphite coated with amorphous carbon (GC) through the Chemical Vapor Deposition (CVD) method. The coated carbon layer at the graphite interface exhibits enhanced reaction kinetics and expanded lithium-ion diffusion pathways, thereby reduction in polarization effectively alleviates the risk of lithium precipitation during rapid charging and low-temperature operation. The pouch cell incorporating GC‖LiCoO exhibits exceptional durability, retaining 87% of its capacity even after 1200 cycles at a high charge/discharge rate of 5C/5C. Remarkably, at -20 °C, the GC-2 maintains a specific capacity of 163 mA h g at 0.5C, higher than that of pristine graphite (65 mA h g). Even at -40 °C, the GC-2‖LiCoO pouch cell still shows excellent capacity retention. This design realizes the practical application of graphite anode in extreme environments, and have a promising prospect of application.
随着锂离子电池市场的不断扩大,解决锂离子电池(LIBs)稳定循环和低温运行的关键问题已成为当务之急。LIBs中原位石墨的高各向异性和较差的动力学性能导致锂枝晶沉淀的形成,特别是在快速充电或低温运行期间。在本研究中,我们通过化学气相沉积(CVD)方法设计了一种涂覆有无定形碳(GC)的石墨。石墨界面处的涂覆碳层表现出增强的反应动力学和扩展的锂离子扩散路径,从而有效降低极化,减轻了快速充电和低温运行期间锂沉淀的风险。包含GC‖LiCoO的软包电池表现出卓越的耐久性,即使在5C/5C的高充/放电速率下经过1200次循环后仍保留其容量的87%。值得注意的是,在-20°C时,GC-2在0.5C下保持163 mA h g的比容量,高于原位石墨(65 mA h g)。即使在-40°C时,GC-2‖LiCoO软包电池仍表现出优异的容量保持率。这种设计实现了石墨负极在极端环境中的实际应用,并具有广阔的应用前景。