The carbon layer with good electrical conductivity and outstanding mechanical stability are essential in designing high-performance silicon/carbon (Si/C) anodes to replace the commercial graphite in lithium-ion batteries (LIBs). In terms of solving the two inherent defects of poor conductivity and big volume change of silicon, we fabricate a spongy carbon matrix derived from ZIF-8 to anchor saclike silicon synthesized by molten salt magnesiothermic reduction method. This spongy matrix can anchor saclike silicon to provide a stable reaction interface and support fast electronic transmission. At the same time, buffer space in saclike Si nanoparticles and spongy matrix can synergistically accommodate the volume change of Si to maintain the integrity of the electrode. The resulting composite with a high Si content of 77.58% exhibits good capacities of 1448 mAh g-1 at 2 A g-1 and 848 mAh g-1 at 4 A g-1 after 500 cycles. High initial coulombic efficiency of 84% at 0.2 A g-1 is also exhibited in the first three activation cycles. Therefore, this novel multifunctional N-doped spongy matrix can supply multifaceted benefits in accommodation of volumetric variation, enhancement of conductivity, and integrity of structure during cycling.

中文翻译：

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锚定在ZIF-8衍生的海绵状基质中的囊状硅纳米颗粒是锂离子电池的高性能阳极。

碳层具有良好的导电性和出色的机械稳定性，对于设计高性能的硅/碳（Si / C）阳极以替代锂离子电池（LIB）中的商用石墨至关重要。为了解决硅导电性差和体积变化大的两个固有缺陷，我们制备了一种由ZIF-8衍生的海绵状碳基体，以锚固通过熔融盐镁热还原法合成的囊状硅。这种海绵状基质可以锚定囊状硅，以提供稳定的反应界面并支持快速的电子传输。同时，囊状硅纳米颗粒和海绵状基质中的缓冲空间可以协同适应硅的体积变化，从而保持电极的完整性。所得复合材料的高Si含量为77。58％的电池经过500次循环后，在2 A g-1下显示1448 mAh g-1的良好容量，在4 A g-1下显示848 mAh g-1的良好容量。在最初的三个活化周期中，在0.2 A g-1时也显示出84％的高初始库仑效率。因此，这种新颖的多功能氮掺杂海绵状基质可以在循环过程中适应体积变化，提高电导率和结构完整性方面提供多方面的好处。