Constructing adaptive silicon–carbon interconnected network for high-energy lithium-ion batteries

• Published in: Carbon (New York) Vol. 226; p. 119195
• Main Authors: Li, Zhaojin, Shi, Conghao, Liu, Pengfei, Di, Yunbo, Zhang, Di, Wang, Qiujun, Sun, Huilan, Sun, Qujiang, Wang, Bo
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2024
• Subjects: Anode material; anodes; cathodes; energy; graphene; heat treatment; industrialization; Lithium-ion batteries; melamine; Silicon/graphite composite material; Silicon–carbon interconnection network; Lithium-ion batteries; Anode material; Silicon–carbon interconnection network; Silicon/graphite composite material
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2024.119195

Nano-silicon (n-Si)/graphite anodes are highly desirable for high-energy lithium-ion batteries. Nevertheless, the high surface energy of n-Si grains is prone to causing serious agglomeration. In this work, the modified n-Si is evenly dispersed on the g-C3N4 carbon mesh that acquired through melamine heat treatment constructing an adaptive Si-carbon interconnection network structure (mSi50/g-C3N4). Ideally, the mSi50/g-C3N4 composite can be well dispersed and fill the gaps in graphite through traditional ball milling processes. The obtained mSi50/g-C3N4/Gr composite prevents the accumulation of Si grains which is beneficial for expediting ion transport, improving conductivity and structural stability. As a result, this anode provides a reversible capacity of 621 mAh⋅g−1 at 0.2 C, with high-capacity retention of 93.3 % after 300 cycles at 1 C and low volume expansion of only 28.6 %. Furthermore, it also maintains excellent cycling stability in full batteries with LiFePO4 cathode. Therefore, constructing the mSi50/g-C3N4 network is an effective strategy to achieve uniform dispersion of Si in graphite and promote larger scale industrialization of n-Si/graphite anode. The adaptive Si-carbon interconnection network structure was achieved, which is dedicated to the uniform dispersion of Si on the surface of graphite. [Display omitted] •The mSi50/g-C3N4 is obtained by dispersing of modified Si on g-C3N4 carbon mesh that acquired through melamine treatment.•The mSi50/g-C3N4/Gr composite prevents the accumulation of Si grains which is beneficial for expediting ion transport.•The mSi50/g-C3N4/Gr provides a capacity of 621 mAh⋅g−1 at 0.2 C, with a retention rate of 93.3 % after 300 cycles.