Metal Organic Frameworks (MOFs) Cooperated Si Nanorod Arrays Used in Rechargeable Batteries

Given the large surface area and unique channels, metal-organic frameworks (MOFs),¹ have  served as a “generalist” in the fields of clean energy,² such as adsorbents for hydrogen,³ electrolytes for fuel cells,⁴ electrode materials for supercapacitors⁵ and so on. However, only a few immature applications of MOFs as electrodes for lithium ion batteries (LIBs) or micro-LIBs have been researched.^6-9To the contrary, Si anode, with the highest theoretical capacity, low working potential and feasible integration with other micro- or nano-electronic devices, has been intensively investigated experimentally and theoretically to address the volume expansion issue during discharge/charge processes. But, fully addressing the deterioration of the electrode structures caused by the volume expansion, which would generally results in performance fading and safety issues, is still challenging.

In this work, a novel class of MOFs, was initially proposed to composite/network with Si nanorod (NR) arrays as anodes for LIBs employing the modified nanosphere lithography (NSL) and inductive coupled plasma (ICP) dry etching followed by a method of solution growth. An enhanced capacity was accomplished in this hybrid material nanocomposite electrode compare with that in the only Si NR anodes. In addition, with the employment of a buffer layer of Ti/TiN to modify the electronic conductivity of the interfaces between Si inner core and outer MOFs, a further enhanced capacity was realized accompanied with the high Coulombic Efficiency (CE).First principles calculations were performed to verify the favorable lithium diffusion in the MOF cooperated Si structure.

References:

[1] Li, H.; Eddaoudi, M.; O’Keeffe, M.; Yaghi, O. M. Nature 1999, 402, 276.

[2] Li, S.-L; Xu, Q. Energy. Environ. Sci. 2013, 6, 1656.

[3] Rosi, N. L.; Eckert, J.; Eddaoudi, M.; Vodak, D. T.; Kim, J.; O’Keeffe, M.; Yaghi, O.M. Science 2003, 300, 1127.

[4] Nagao, Y.; Fujishima, M.; Ikeda, R.; Kitagawa, H. Synth. Met. 2003, 123, 133.

[5] DÍaz, R.; Orcajo, M. G.; Botas, J. A.; Calleja, G.; Palma, J.  Mater. Lett. 2012, 68, 126.

[6] Barthelet, K.; Marrot, J.; Riou, D.; Férey, G. Angew. Chem., Int. Ed. 2002, 41, 281.

[7]  Zheng, X.; Li, Y.; Xu, Y.; Hong, Z.; Wei, M. CrystEngComm 2012, 14, 2112.

[8] Wessells, C. D.; Huggins, R. A.; Cui, Y. Nat. Commun. 2011, 2, 550.

[9] Han, Y.; Qi, P.; Li, S.; Feng, X.; Zhou, J.; Li, H.; Su, S.; Li, X.; Wang, B. Chem. Commun. 2014, 50, 8057.