Nanosilicon/graphite composites have high specific capacity in lithium-ion batteries (LIBs). However, there exist low initial Coulombic efficiency (ICE) and low tap density problems caused by the high specific surface area (SSA) of nanosilicon. Therefore, the porous structural design of silicon has become another choice. This work reports the facile preparation of micrometer-sized porous silicon by a single-roller rapid solidification technique followed by acid etching. Coral-like porous silicon (CPSi-1) with appropriate skeleton size, SSA, and porosity has been synthesized. CPSi-1 exhibits an initial discharge/charge specific capacity of 3389.4/2904.7 mAh g^–1, and the reversible specific capacity of 705 mAh g^–1 is retained after 100 cycles at a current density of 1 A g^–1. The CPSi-1@graphite/carbon composites (CPSi@G/C-1), prepared by a simple liquid-phase solidification method with obtained CPSi-1, graphite (G), and asphalt, exhibit an initial reversible specific capacity of 709.3 mAh g^–1 and a capacity retention of 86.7% after 100 cycles at 0.2 A g^–1. The CPSi@G/C-1||Li(Ni_0.6Co_0.2Mn_0.2)O₂ (NCM622) coin-type full-cell shows a reversible specific capacity of 101.1 mAh g^–1 after 100 cycles at 0.5 C with an average CE of 99.2%. This work provides a facile and scalable industrial production technology for micrometer-sized porous silicon and porous silicon/graphite composites.

中文翻译：

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用于锂离子电池的类珊瑚多孔硅/石墨复合材料

纳米硅/石墨复合材料在锂离子电池（LIB）中具有高比容量。然而，纳米硅的高比表面积（SSA）导致存在初始库仑效率（ICE）低和振实密度低的问题。因此，硅的多孔结构设计成为了另一种选择。这项工作报告了通过单辊快速凝固技术随后进行酸蚀刻轻松制备微米级多孔硅。合成了具有适当骨架尺寸、SSA和孔隙率的珊瑚状多孔硅（CPSi-1）。 CPSi-1的首次放电/充电比容量为3389.4/2904.7 mAh g ^{–1 ，在1 A g –1}的电流密度下循环100次后，可逆比容量保持为705 mAh g ^–1。以CPSi-1、石墨（G）和沥青为原料，通过简单的液相固化方法制备CPSi-1@石墨/碳复合材料（CPSi@G/C-1），其初始可逆比容量为709.3 mAh g ^{–1且在 0.2 A g –1}下循环 100 次后容量保持率为 86.7% 。 CPSi@G/C-1||Li(Ni _0.6 Co _0.2 Mn _0.2 )O ₂ (NCM622)纽扣型全电池在0.5 C下循环100次后平均可逆比容量为101.1 mAh g ^–1 CE 为 99.2%。这项工作为微米级多孔硅和多孔硅/石墨复合材料提供了一种简便且可扩展的工业生产技术。