Speaker: Prof. Yanglong Hou
Date: Friday , June 19, 2015
Time: 15:00 - 17:00
Venue: C102
Abstract:
Presently, safe energy storage is one of the most demanding technologies by the developing society. In this regard, lithium ion batteries (LIBs) and Supercapacitors (SC) have got tremendous attention due to their high energy and power densities; have been considered as promising power source for future electric vehicles (EVs). Thus, most of the present research is focused to develop new electrode materials that can bring the realization of these devices for EVs. However, structural disintegration, limited access to redox sites and loss of electrical contact have long been identified as primary reasons for capacity loss and poor cyclic life of these materials. Although nanotechnology plays critical role by developing nanostructures but simple reduction in size introduce new fundamental issues like side reactions and thermally less stable. Thus, a careful design that can inhibit the side reaction by surface protection, make all redox sites accessible by increasing the intrinsic conductivity of the active materials, maintain a continues network for ionic and electronic flow and keeps the structural integrity, resulting improved performance and excellent capacity retention with long cyclic life to meet the requirements set by USABC for electrode materials to use them in EVs. Here, we have developed different hybrid structures of metal oxides, nitrides, sulfides, hydroxides and metal alloys with doped graphene to control above mentioned problems and to achieve the goals set by USABC. All these composites possess extraordinary performances as electrodes of LIBs and SC with long cyclic stability and excellent rate capability. The high performance of the composites based on the synergistic effect of several components in the nanodesign. These strategies to combine the different property enhancing factors in one composite with engineered structures will bring the realization of these devices in road market.
References
1. Mahmood, N.; Zhu, J.; Rehman, S.; Li, Q. and Hou, Y. Nano Energy, 11, in press (2015).
2. Mahmood, N.; Tahirb, M.; Mahmood, A.; Zhu, J.; Cao, C. and Hou, Y., Nano Energy, 11, 267–276 (2015).
3. Mahmood, N. and Hou, Y., Adv. Sci., 1, 1400012 (2014).
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5. Zhang, C.; Hao, R.; Liao H. and Hou, Y., Nano Energy, 2, 88-97 (2013).
6. Zhang, C.; Mahmood, N.; Yin, H.; Liu, F. and Hou, Y., Adv Mater, 25, 4932–4937 (2013).
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