Ke Qingqing, Zhang Xiao, Zang Wenjie, Elshahawy Abdelnaby M, Hu Yating, He Qiyuan, Pennycook Stephen J, Cai Yongqing, Wang John
Department of Materials Science and Engineering, National University of Singapore, Singapore, 117574, Singapore.
Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
Small. 2019 May;15(21):e1900131. doi: 10.1002/smll.201900131. Epub 2019 Apr 24.
Transition metal dichalcogenides exhibit several different phases (e.g., semiconducting 2H, metallic 1T, 1T') arising from the collective and sluggish atomic displacements rooted in the charge-lattice interaction. The coexistence of multiphase in a single sheet enables ubiquitous heterophase and inhomogeneous charge distribution. Herein, by combining the first-principles calculations and experimental investigations, a strong charge transfer ability at the heterophase boundary of molybdenum disulfide (MoS ) assembled together with graphene is reported. By modulating the phase composition in MoS , the performance of the nanohybrid for energy storage can be modulated, whereby remarkable gravimetric and volumetric capacitances of 272 F g and 685 F cm are demonstrated. As a proof of concept for energy application, a flexible solid-state asymmetric supercapacitor is constructed with the MoS -graphene heterolayers, which shows superb energy and power densities (46.3 mWh cm and 3.013 W cm , respectively). The present work demonstrates a new pathway for efficient charge flow and application in energy storage by engineering the phase boundary and interface in 2D materials of transition metal dichalcogenides.
过渡金属二硫属化物呈现出几种不同的相（例如，半导体2H相、金属1T相、1T'相），这些相源于电荷-晶格相互作用引起的集体且缓慢的原子位移。单片中多相的共存使得异相和不均匀电荷分布无处不在。在此，通过结合第一性原理计算和实验研究，报道了二硫化钼（MoS₂）与石墨烯组装在一起时在异相边界处具有很强的电荷转移能力。通过调节MoS₂中的相组成，可以调节这种纳米杂化物的储能性能，从而展示出272 F g⁻¹和685 F cm⁻³的显著重量和体积电容。作为能量应用的概念验证，用MoS₂-石墨烯异质层构建了一种柔性固态不对称超级电容器，其显示出出色的能量和功率密度（分别为46.3 mWh cm⁻³和3.013 W cm⁻³）。本工作通过设计过渡金属二硫属化物二维材料中的相边界和界面，展示了一种用于高效电荷流动及储能应用的新途径。
