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

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-C 3 N 4 carbon mesh that acquired through melamine heat treatment constructing an adaptive Si-carbon interconnection network structure (mSi 50 /g-C 3 N 4). Ideally, the mSi 50 /g-C 3 N 4 composite can be well dispersed and fill the gaps in graphite through traditional ball milling processes. The obtained mSi 50 /g-C 3 N 4 /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 LiFePO 4 cathode. Therefore, constructing the mSi 50 /g-C 3 N 4 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 mSi 50 /g-C 3 N 4 is obtained by dispersing of modified Si on g-C 3 N 4 carbon mesh that acquired through melamine treatment. • The mSi 50 /g-C 3 N 4 /Gr composite prevents the accumulation of Si grains which is beneficial for expediting ion transport. • The mSi 50 /g-C 3 N 4 /Gr provides a capacity of 621 mAh⋅g−1 at 0.2 C, with a retention rate of 93.3 % after 300 cycles. [ABSTRACT FROM AUTHOR]