Silicon electrodes with the columnar macroporous structure were investigated to determine the effect of variations in the columnar pore morphology on lithiation and energy storage capacity in Li-ion cells. Several variants of macroporous Si columnar electrodes were electrochemically cycled against the Li reference electrode. The changes in macro-pore size and Si wall thickness of the columnar architecture greatly affected the cyclic Li storage and discharge capacities. A strong correlation of the Li-storage capacity with the ratio of Si wall thickness to pore diameter is found to exist. Specifically, one columnar Si electrode with an optimum macroporous structure exhibited a very high reversible specific capacity of ~1250 mAh/g (total capacity 1.2 mAh/cm2) for over 200 cycles. Electron microscopy revealed that the high reversible Li-storage capacity is due to the macropores accommodating the change in volume of lithiation and providing nearly complete reconstruction of Si walls upon delithiation. The present observations can lead to practical, high-capacity, and damage-resistant Si electrodes for Li-ion batteries.

研究了具有柱状大孔结构的硅电极，以确定柱状孔形貌变化对锂离子电池的锂化和储能能力的影响。大孔Si柱状电极的几种变体相对于Li参比电极进行电化学循环。柱状结构的大孔尺寸和硅壁厚的变化极大地影响了循环锂的存储和放电容量。发现存在锂存储容量与Si壁厚与孔径的比率的强相关性。具体而言，具有最佳大孔结构的一个圆柱状Si电极具有非常高的可逆比容量，约为〜1250 mAh / g（总容量1.2 mAh / cm 2）超过200个周期。电子显微镜显示，高可逆的锂存储容量是由于大孔适应锂化体积的变化，并在脱锂时提供了几乎完整的硅壁重建。目前的观察结果可能会导致实用，高容量且抗损坏的锂离子电池Si电极。