Three-Dimensional Porous Silicon Particles for Use in High-Performance Lithium Secondary Batteries
Three-Dimensional Porous Silicon Particles for Use in High-Performance Lithium Secondary Batteries
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DOI：
10.1002/anie.200804355
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发表时间：
2008-01-01
影响因子：
16.6
通讯作者：
Cho, Jaephil
中科院分区：
文献类型：
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作者：
Kim, Hyunjung;Han, Byunghee;Cho, Jaephil
硅已被研究用作下一代高容量阳极材料，因为其理论锂容量约为4140 mA hg/m2（ca. Li 4. 4Si）的容量是石墨（约11倍）的容量。372 mA hg 1），[1]目前用作阳极材料。尽管硅的容量高，但在锂合金化（以形成LixSi）和去合金化（以改革Si）期间，可通过大的体积变化（> 300%）触发严重的颗粒粉碎，这导致电断开的较小颗粒。这些断开的颗粒导致循环稳定性的快速降低。密集的研究集中在通过使用具有非活性碳相的复合材料来减少这种体积变化，以防止颗粒生长的聚集，并在颗粒被粉碎时充当阳极颗粒和集电器之间的电连接介质。[2-11]然而，这些方法导致充电容量在数十次循环后下降至小于1500 mAhgg-1。另一方面，很少报道通过控制Si的形态来控制体积变化。Chan埃塔尔已经报道了Si纳米线，其在0.05 ℃的速率下显示出约2900 mAh·g-1的可逆容量，其生长在金属集电器上。[12]然而，在2C速率下的容量保持率小于初始容量的50%。Ma等人报道了巢状Si颗粒的首次充电容量为3952 mAhgg-1，但在50次循环后，在0.5C的速率下，在1.6V和0.02V之间，颗粒的容量保持率为36%。[13]最近，Liu及其同事证明了通过使用电化学沉积工艺制造的Cu和Sn的3D金属泡沫结构不仅表现出锂离子通过电解质和电极的快速传输，而且还表现出快速的电化学反应，这导致具有上级倍率性能的高性能阳极。[14-16]例如，Cu 6Sn 5合金在20 C循环速率下显示出45%的容量保持率，但是，由于非常厚的孔壁（> 100 μm），在40次循环后容量衰减明显。[14]到目前为止，除了来自镁合金的那些之外，还没有关于合成3D多孔Si颗粒的报道。
Silicon has been investigated for use as a next-generation, high-capacity anode material as its theoretical lithium capacity of approximately 4140 mA hg À1(ca. Li4. 4Si) is eleven times higher than the capacity of graphite (ca. 372 mA hg À1),[1] which is currently used as an anode material. In spite of the high capacity of silicon, severe particle pulverization can be triggered by a large volume change (> 300%) during lithium alloying (to form LixSi) and de-alloying (to reform Si), which results in electrically disconnected smaller particles. These disconnected particles cause a rapid decrease in cycling stability. Intense studies have focused on reducing this volume change by using composites with an inactive carbon phase to prevent the aggregation of particle growth and to act as electrically connecting media between anode particles and the current collector when the particle is pulverized.[2–11] However, these methods lead to a decrease in the charge capacity to less than 1500 mAhgÀ1 after dozens of cycles. On the other hand, control of the volume change by control of the morphology of the Si has very rarely been reported. Chan etal. have reported Si nanowires that showed a reversible capacity of approximately 2900 mA hg À1 at a rate of 0.05 C, which were grown on a metallic current collector.[12] However, the capacity retention at a 2 C rate was less than 50% of the initial capacity. Ma et al. reported a first-charge capacity of 3952 mAhgÀ1 for nestlike Si particles, but the capacity retention of the particles was 36% between 1.6 V and 0.02 V at a rate of 0.5 C after 50 cycles.[13]Recently, Liu and co-workers demonstrated that 3D metal foam structures of Cu and Sn fabricated by using an electrochemical deposition process exhibited not only fast transport of lithium ions through the electrolyte and the electrode, but also rapid electrochemical reactions, which resulted in a high performance anode with a superior rate capability.[14–16] For instance, a Cu6Sn5 alloy showed a 45% capacity retention at a 20 C cycling rate, but, because of a very thick pore wall (> 100 μm), capacity fade was pronounced after 40 cycles.[14] To date, there have been no reports of the synthesis of 3D porous Si particles, with the exception of those from the magnesio-