Energy Storage
The rapid development of flexible and stretchable electronics has triggered extensive efforts to explore matching flexible and stretchable energy storage devices as power sources. A series of designs and constructions for flexible and stretchable batteries have been investigated in recent years. Particularly, significant progress has been achieved in finding high-performance electrolyte and electrode materials as well as new structural designs. Typical commercial devices consist of a carbon-based anode separated from a transition metal-oxide cathode by a liquid electrolyte composed of a lithium salt dissolved in an organic solvent. While these batteries are ubiquitous across a wide range of applications, the technology still suffers from safety hazards, which is significantly problematic for wearable and implantable electronics. Solid-state electrolytes would be a perfect solution to not only solve most of the safety issues encountered with liquid electrolytes but also offer possibilities for developing new battery chemistries. Polymer electrolytes offer several advantages over liquid electrolytes and inorganic solid electrolytes, such as high stability with lithium metal, excellent flexibility, and high level of safety. Moreover, dendrite growth could be minimized or even suppressed in solvent-free polymer electrolytes under certain conditions. The development of polymer electrolytes has been hindered by three issues: low ionic selectivity, low oxidation voltage, and narrow operating temperature. One strategy for overcoming the problems related to binary ionic conducting electrolytes is to develop a single ion conductor by anchoring the anion into the polymer framework. In these systems, Li cation must hop between the immobilized anions in order to traverse the electrolyte, which improves the ion selectivity in conduction leading to a much longer cycle life. Also, this material can achieve a high oxidation voltage and minimization of dendrite growth by controlling the anion distribution at the interface. We recently have developed a new class of lithium-conducting polymer electrolytes based on porous aromatic frameworks (PAFs) [1-3] that are amenable to straightforward chemical modification. The intrinsic interpenetration of individual networks enables the functional groups in close proximity, allowing for great beneficial effects on ionic conduction. The apparent tuneability of the PAFs holds promise for the development of new materials for flexible and stretchable energy storage devices. The proposed research will be dedicated to: (1) the development of novel single-ion conducting network-inspired polymer electrolytes in which anionic nodes and functionalized organic bridges facilitate the transport of lithium ions [4], and (2) the modification of these network-inspired polymer electrolytes to generate flexible and stretchable conductors for wearable and implantable batteries.
[1] J. F. Van Humbeck, M. L. Aubrey, A. Alsbaiee, R. Ameloot, G. W. Coates, W. R. Dichtel, J. R. Long, Chemical Science (2015) 6, 5499-5505.
[2] Dong.-Myeong Shin, J. E. Bachman, M. K. Taylor, J. Kamcev, J. G. Park, M. E. Ziebel, E. Velasquez, N. N. Jarenwattananon, G. K. Sethi, Y. Cui, J. R. Long, Advanced Materials (2020) 32, 1905771.
[3] Jingyi Gao†, Cong Wang†, D.-W. Han, Dong-Myeong Shin*, Chemical Science (2021) 12, 13248.
[4] Jingyi Gao, Jiaming Zhou, Cong Wang, Xiaoting Ma, Ke Jiang, Eunjong Kim, C. Li, H. Liu, L. Xu, H. C. Shum, S.-P. Feng, Dong.-Myeong Shin*, Chemical Engineering Journal (2022) 450, 138407.