Shixue Zhang, Yu Li, Hang Xu, Cong Peng, Lingchen Kong, Zhihao Gui and Wei Feng
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引用次数: 0
Abstract
Li/CFx batteries are an essential energy source for advancing smart medicine and deep-space exploration, yet increasing their energy density is crucial for large-scale applications. However, CFx cathode development is hindered due to the voltage–capacity trade-off when the actual synthesis is considered. To solve this problem, the mechanism of fluorination and key factors that affect the fluorine pattern must be determined. In this study, we propose a diffusion-controlled fluorination mechanism, and the critical role of the carbon source structure in the fluorination kinetics and fluorine pattern of the formed CFx is revealed. As a proof-of-concept, we prepared a series of hierarchical porous carbons (HPCs) and promoted fluorination kinetics with their well-developed hierarchical pore structure, achieving a high fluorine content from full interior fluorination and an altered fluorine pattern. In addition, the low fluorination temperature enabled by HPCs helped preserve the skeleton structure and improve the conductivity, resulting in an excellent maximum energy density of 2902.45 W h kg−1 (0.05C) and power density of 74.837 kW kg−1 at 50C. Orthogonal experiments, which facilitated the tailoring of battery performance, demonstrated the synergistic effect of the carbon source and fluorination temperature for the first time. This study provides theoretical and practical guidance for designing and implementing CFx cathodes for ultrahigh-energy-density Li/CFx batteries, and the results pave the way for various large-scale applications of Li/CFx batteries in the future.
期刊介绍:
The Journal of Materials Chemistry A, B & C covers a wide range of high-quality studies in the field of materials chemistry, with each section focusing on specific applications of the materials studied. Journal of Materials Chemistry A emphasizes applications in energy and sustainability, including topics such as artificial photosynthesis, batteries, and fuel cells. Journal of Materials Chemistry B focuses on applications in biology and medicine, while Journal of Materials Chemistry C covers applications in optical, magnetic, and electronic devices. Example topic areas within the scope of Journal of Materials Chemistry A include catalysis, green/sustainable materials, sensors, and water treatment, among others.