Changzheng Wu1

1, University of Science and Technology of China, Hefei, Anhui, China

Flexible supercapacitors with high energy density and excellent mechanical property are now emerging energy storage devices for future stretchable electronics. Two-dimensional (2D) inorganic solids have been regarded as potential promising candidates for various applications1,2,3 especially for flexible supercapacitors with superior electrochemical performance.
Summarized herein are our group’s recent progress on realizing high-performance flexible supercapacitors based on 2D inorganic solids, specifically focusing on tuning the intrinsic electric properties of electrode as well as developing new gel electrolyte4. Inspired by metallic nature of 2D materials, such as ultrathin VS2 and TaS2 nanosheets, we constructed a series of in-plane supercapacitors by utilizing synergic advantages of high conductivity and high specific area, demonstrating a remarkable improved specific capacitance with bend tolerance5. Furthermore, we realized supercapacitors assembled by 2D VN and TiN mesocrystal nanosheets with superior conductivity and highly open nanostructures6. Then, to explore potential of 2D pseudocapacitance materials, layer-by-layer MnO2/graphene was further designed to overcome their intrinsic poor conductivity and achieve huge performance promotion. Beside, we also developed a novel zwitterionic gel electrolyte PPDP/LiCl for 2D solid-state supercapacitor, greatly enhancing performance of graphene supercapacitor7.
In summary, 2D nanomaterials have shown the promising advantages of high specific surface area, excellent mechanical performance and potential pseudocapacitive behavior that are vital for the construction of flexible supercapacitors. Our recent work on both 2D electrodes and gel electrolyte represent a promising direction for building future-generation high-performance, flexible energy storage devices.

1. X. Peng, Y. Guo, Q. Yin, J. Wu, J. Zhao, C. Wang, S. Tao, W. Chu, C. Wu*, Y. Xie, J. Am. Chem. Soc. 2017, 139, 5242.
2. J. Peng, J. Wu, X. Li, Y. Zhou, Z. Yu, Y. Guo, J. Wu, Y. Lin, Z. Li, X. Wu, C. Wu*, Y. Xie, J. Am. Chem. Soc. 2017, 139, 9019.
3. Y. Guo, H. Deng, X. Sun, X. Li, J. Zhao, J. Wu, W. Chu, S. Zhang, H. Pan, X. Zheng, X. Wu*, C. Jin*, C. Wu*, Y. Xie, Adv. Mater.2017, 29, 1700715.
4. X. Peng, L. Peng, C. Wu*, Y. Xie, Chem. Soc. Rev. 2014, 43, 3303.
5. J. Feng, X. Sun, C. Wu*, L. Peng, C. Lin, S. Hu, J. Yang, Y. Xie*, J. Am. Chem. Soc. 2011, 133, 17832.
6. W. Bi, Z. Hu, X. Li, C. Wu*, J. Wu, Y. Wu, Y. Xie, Nano Res. 2015, 8, 193.
7. X. Peng, H. Liu, Q. Yin, J. Wu, P. Chen, G. Zhang, G. Liu*, C. Wu*, Y. Xie, Nat. Commun. 2016, 7, 11782.