Three-Dimensionally Engineered Porous Silicon Electrodes for Li Ion Batteries
Three-Dimensionally Engineered Porous Silicon Electrodes for Li Ion Batteries
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DOI：
10.1021/nl302114j
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发表时间：
2012-12-01
期刊：
影响因子：
10.8
通讯作者：
Reddy, Arava Leela Mohana
中科院分区：
文献类型：
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作者：
Gowda, Sanketh R.;Pushparaj, Victor;Reddy, Arava Leela Mohana
锂离子电池设计的最终目标应该包括完全可接近的金属集电器，可能具有纳米级尺寸，与高容量稳定的电极材料密切接触。在这里，我们设计了三维多孔镍基集流体，该集流体保形地涂覆有硅层，其通常具有较差的循环寿命，以形成高容量电极。这些不含粘合剂/导电添加剂的硅电极显示出优异的电极粘附性，从而导致上级循环稳定性和倍率性能。镍集电器设计还允许每单位面积的硅负载增加，导致高达0.8mAh/cm（2）的高面积放电容量，而不会显著损失倍率容量。优异的电极利用率（类似于85%）和金属/硅系统的改善的循环稳定性归因于在循环期间电极膨胀时降低的内应力/断裂以及有助于改善较厚硅层的倍率性能的较短的离子/电子扩散路径。
The ultimate goal of Li ion battery design should consist of fully accessible metallic current collectors, possibly of nanoscale dimensions, intimately in contact with high capacity stable electrode materials. Here we engineer three-dimensional porous nickel based current collector coated conformally with layers of silicon, which typically suffers from poor cycle life, to form high-capacity electrodes. These binder/conductive additive free silicon electrodes show excellent electrode adhesion resulting in superior cydic stability and rate capability. The nickel current collector design also allows for an increase in silicon loading per unit area leading to high areal discharge capacities of up to 0.8 mAh/cm(2) without significant loss in rate capability. An excellent electrode utilization (similar to 85%) and improved cyclic stability for the metal/silicon system is attributed to reduced internal stresses/fracture upon electrode expansion during cycling and shorter ionic/electronic diffusion pathways that help in improving the rate capability of thicker silicon layers.