Department of Materials Science and Engineering, Korea University , Seongbuk-gu, Anam-ro 145, Seoul, Republic of Korea.
ACS Nano. 2014 Feb 25;8(2):1907-12. doi: 10.1021/nn406464c. Epub 2014 Jan 23.
We present an amorphous Si anode deposited on a Cu nanopillar current collector, fabricated using a thermal roll-to-roll process followed by electroformation and LPCVD, for application in high-rate Li-ion batteries. Cu nanopillar current collectors with diameters of 250 and 500 nm were patterned periodically with 1 μm pitch and 2 μm height to optimize the diameters of the pillars for better electrochemical performance. Void spaces between Cu nanopillars allowed not only greater effective control of the strain caused by the Si expansion during lithiation than that allowed by a nonpatterned electrode but also significantly improved cycle performance even at 20 C measured after the same rate test: After 100 cycles at 0.5 C, the patterned electrodes with 250 and 500 nm diameter nanopillars showed high capacity retentions of 86% and 84%, respectively. These electrodes retained discharge capacities of 1057 and 780 mAh/g even at 20 C, respectively.
我们提出了一种在 Cu 纳米柱集流体上沉积的非晶态硅阳极，该集流体是使用热滚压工艺随后进行电铸和 LPCVD 制备的，用于高倍率锂离子电池。使用直径为 250nm 和 500nm 的 Cu 纳米柱以 1μm 的间距和 2μm 的高度周期性地进行图案化，以优化柱的直径以获得更好的电化学性能。Cu 纳米柱之间的空隙不仅允许更好地控制 Si 在锂化过程中膨胀引起的应变，而且比非图案化电极允许的应变更好，而且即使在经过相同倍率测试后，循环性能也得到了显著改善：在 0.5 C 下经过 100 次循环后，直径为 250nm 和 500nm 的纳米柱的图案化电极分别具有 86%和 84%的高容量保持率。这些电极在 20 C 时仍分别保持 1057 和 780 mAh/g 的放电容量。
