title: Supercapacitors of nanocrystalline metal-organic frameworks.
abstract: The high porosity of metal-organic frameworks (MOFs) has been used to achieve exceptional gas adsorptive properties but as yet remains largely unexplored for electrochemical energy storage devices. This study shows that MOFs made as nanocrystals (nMOFs) can be doped with graphene and successfully incorporated into devices to function as supercapacitors. A series of 23 different nMOFs with multiple organic functionalities and metal ions, differing pore sizes and shapes, discrete and infinite metal oxide backbones, large and small nanocrystals, and a variety of structure types have been prepared and examined. Several members of this series give high capacitance; in particular, a zirconium MOF exhibits exceptionally high capacitance. It has the stack and areal capacitance of 0.64 and 5.09 mF cm(-2), about 6 times that of the supercapacitors made from the benchmark commercial activated carbon materials and a performance that is preserved over at least 10000 charge/discharge cycles.
authors.affiliation: Department of Chemistry, University of California-Berkeley , Materials Sciences Division at Lawrence Berkeley National Laboratory, and Kavli Energy NanoSciences Institute at Berkeley, Berkeley, California 94720, United States.
authors.forename: Kyung Min
authors.initials: KM
authors.lastname: Choi
authors.forename: Hyung Mo
authors.initials: HM
authors.lastname: Jeong
authors.forename: Jung Hyo
authors.initials: JH
authors.lastname: Park
authors.forename: Yue-Biao
authors.initials: YB
authors.lastname: Zhang
authors.forename: Jeung Ku
authors.initials: JK
authors.lastname: Kang
authors.forename: Omar M
authors.initials: OM
authors.lastname: Yaghi