Hierarchical Cobalt Hydroxide and B/N Co-Doped Graphene Nanohybrids Derived from Metal-Organic Frameworks for High Energy Density Asymmetric Supercapacitors.

Title Hierarchical Cobalt Hydroxide and B/N Co-Doped Graphene Nanohybrids Derived from Metal-Organic Frameworks for High Energy Density Asymmetric Supercapacitors.
Authors H. Tabassum; A. Mahmood; Q. Wang; W. Xia; Z. Liang; B. Qiu; R. Zhao; R. Zou
Journal Sci Rep
DOI 10.1038/srep43084
Abstract

To cater for the demands of electrochemical energy storage system, the development of cost effective, durable and highly efficient electrode materials is desired. Here, a novel electrode material based on redox active ?-Co(OH)2 and B, N co-doped graphene nanohybrid is presented for electrochemical supercapacitor by employing a facile metal-organic frameworks (MOFs) route through pyrolysis and hydrothermal treatment. The Co(OH)2 could be firmly stabilized by dual protection of N-doped carbon polyhedron (CP) and B/N co-doped graphene (BCN) nanosheets. Interestingly, the porous carbon and BCN nanosheets greatly improve the charge storage, wettability, and redox activity of electrodes. Thus the hybrid delivers specific capacitance of 1263 F?g(-1) at a current density of 1A?g(-1) with 90% capacitance retention over 5000 cycles. Furthermore, the new aqueous asymmetric supercapacitor (ASC) was also designed by using Co(OH)2@CP@BCN nanohybrid and BCN nanosheets as positive and negative electrodes respectively, which leads to high energy density of 20.25?Whkg(-1). This device also exhibits excellent rate capability with energy density of 15.55?Whkg(-1) at power density of 9331?Wkg(-1) coupled long termed stability up to 6000 cycles.

Citation H. Tabassum; A. Mahmood; Q. Wang; W. Xia; Z. Liang; B. Qiu; R. Zhao; R. Zou.Hierarchical Cobalt Hydroxide and B/N Co-Doped Graphene Nanohybrids Derived from Metal-Organic Frameworks for High Energy Density Asymmetric Supercapacitors.. Sci Rep. 2017;7:43084. doi:10.1038/srep43084

Related Elements

Cobalt

See more Cobalt products. Cobalt (atomic symbol: Co, atomic number: 27) is a Block D, Group 9, Period 4 element with an atomic weight of 58.933195. Cobalt Bohr ModelThe number of electrons in each of cobalt's shells is 2, 8, 15, 2 and its electron configuration is [Ar]3d7 4s2. The cobalt atom has a radius of 125 pm and a Van der Waals radius of 192 pm. Cobalt was first discovered by George Brandt in 1732. In its elemental form, cobalt has a lustrous gray appearance. Cobalt is found in cobaltite, erythrite, glaucodot and skutterudite ores. Elemental CobaltCobalt produces brilliant blue pigments which have been used since ancient times to color paint and glass. Cobalt is a ferromagnetic metal and is used primarily in the production of magnetic and high-strength superalloys. Co-60, a commercially important radioisotope, is useful as a radioactive tracer and gamma ray source. The origin of the word Cobalt comes from the German word "Kobalt" or "Kobold," which translates as "goblin," "elf" or "evil spirit.

Carbon

See more Carbon products. Carbon (atomic symbol: C, atomic number: 6) is a Block P, Group 14, Period 2 element. Carbon Bohr ModelThe number of electrons in each of Carbon's shells is 2, 4 and its electron configuration is [He]2s2 2p2. In its elemental form, carbon can take various physical forms (known as allotropes) based on the type of bonds between carbon atoms; the most well known allotropes are diamond, graphite, amorphous carbon, glassy carbon, and nanostructured forms such as carbon nanotubes, fullerenes, and nanofibers . Carbon is at the same time one of the softest (as graphite) and hardest (as diamond) materials found in nature. It is the 15th most abundant element in the Earth's crust, and the fourth most abundant element (by mass) in the universe after hydrogen, helium, and oxygen. Carbon was discovered by the Egyptians and Sumerians circa 3750 BC. It was first recognized as an element by Antoine Lavoisier in 1789.

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