title: Flexible all solid state supercapacitor with high energy density employing black titania nanoparticles as a conductive agent.
abstract: Increasing the electrical conductivity of pseudocapacitive materials without changing their morphology is an ideal structural solution to realize both high electrochemical performance and superior flexibility for an all solid state supercapacitor (ASSSC). Herein, we fabricate a flexible ASSSC device employing black titania (TiO2-x:N) decorated two-dimensional (2D) NiO nanosheets as the positive electrode and mesoporous graphene as the negative electrode. In this unique design, NiO nanosheets are used as pseudocapacitive materials and TiO2-x:N nanoparticles serve as the conductive agent. Owing to the excellent electrical conductivity of TiO2-x:N and well defined "particle on sheet" planar structure of NiO/TiO2-x:N composites, the 2D morphology of the decorated NiO nanosheets is completely retained, which efficiently reinforces the pseudocapacitive activity and flexibility of the whole all solid state device. The maximum specific capacitance of fabricated the NiO/TiO2-x:N//mesoporous graphene supercapacitor can reach 133 F g(-1), which is 2 and 4 times larger than the values of the NiO based ASSSC employing graphene and carbon black as the conductive agent, respectively. In addition, the optimized ASSSC displays intriguing performances with an energy density of 47 W h kg(-1) in a voltage region of 0-1.6 V, which is, to the best of our knowledge, the highest value for flexible ASSSC devices. The impressive results presented here may pave the way for promising applications of black titania in high energy density flexible storage systems.
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructures and CAS Key Laboratory of Materials for Energy Conversion, CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P.R. China. huizhang@mail.sic.ac.cn huangfq@mail.sic.ac.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhi
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructures and CAS Key Laboratory of Materials for Energy Conversion, CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P.R. China. huizhang@mail.sic.ac.cn huangfq@mail.sic.ac.cn.
authors.forename: Chongyin
authors.initials: C
authors.lastname: Yang
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructures and CAS Key Laboratory of Materials for Energy Conversion, CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P.R. China. huizhang@mail.sic.ac.cn huangfq@mail.sic.ac.cn.
authors.forename: Tianquan
authors.initials: T
authors.lastname: Lin
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructures and CAS Key Laboratory of Materials for Energy Conversion, CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P.R. China. huizhang@mail.sic.ac.cn huangfq@mail.sic.ac.cn and Beijing National Laboratory for Molecular Sciences and State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P.R. China.
authors.forename: Houlei
authors.initials: H
authors.lastname: Cui
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructures and CAS Key Laboratory of Materials for Energy Conversion, CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P.R. China. huizhang@mail.sic.ac.cn huangfq@mail.sic.ac.cn and Beijing National Laboratory for Molecular Sciences and State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P.R. China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructures and CAS Key Laboratory of Materials for Energy Conversion, CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P.R. China. huizhang@mail.sic.ac.cn huangfq@mail.sic.ac.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructures and CAS Key Laboratory of Materials for Energy Conversion, CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P.R. China. huizhang@mail.sic.ac.cn huangfq@mail.sic.ac.cn and Beijing National Laboratory for Molecular Sciences and State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P.R. China.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Huang