The flexible supercapacitors (SCs) of the conventional sandwich-type structure have poor flexibility due to the large thickness of the final entire device. Herein, we have fabricated a highly flexible asymmetric SC using manganese dioxide (MnO₂) and reduced graphene oxide (RGO) nanosheet-piled hydrogel films and a novel bacterial cellulose (BC)-filled polyacrylic acid sodium salt-Na₂SO₄ (BC/PAAS-Na₂SO₄) neutral gel electrolyte. Apart from being environmentally friendly, this BC/PAAS-Na₂SO₄ gel electrolyte has high viscosity and a sticky property, which enables it to combine two electrodes together. Meanwhile, the intertangling of the filled BC in the gel electrolyte hinders the decrease of the viscosity with temperature, and forms a separator to prevent the two electrodes from short-circuiting. Using these materials, the total thickness of the fabricated device does not exceed 120 μm. This SC device demonstrates high flexibility, where bending and even rolling have no obvious effect on the electrochemical performance. In addition, owing to the asymmetric configuration, the cell voltage of this flexible SC has been extended to 1.8 V, and the energy density can reach up to 11.7 Wh kg-1 at the power density of 441 W kg-1. This SC also exhibits a good cycling stability, with a capacitance retention of 85.5% over 5000 cycles.

Centre of Polymer Systems Tomas Bata University in Zlin Tř T Bati 5678 76001 Zlin Czech Republic

Key Laboratory for Ultrafine Materials of Ministry of Education School of Materials Science and Engineering East China University of Science and Technology Shanghai 200237 China

Zobrazit více v PubMed

Jang H., Park Y.J., Chen X., Das T., Kim M.-S., Ahn J.-H. Graphene-based flexible and stretchable electronics. Adv. Mater. 2016;28:4184–4202. doi: 10.1002/adma.201504245. PubMed DOI

Lee S.-Y., Choi K.-H., Choi W.-S., Kwon Y.H., Jung H.-R., Shin H.-C., Kim J.Y. Progress in flexible energy storage and conversion systems, with a focus on cable-type lithium-ion batteries. Energy Environ. Sci. 2013;6:2414. doi: 10.1039/c3ee24260a. DOI

Zhou G., Li F., Cheng H.-M. Progress in flexible lithium batteries and future prospects. Energy Environ. Sci. 2014;7:1307–1338. doi: 10.1039/C3EE43182G. DOI

Wang X., Lu X., Liu B., Chen D., Tong Y., Shen G. Flexible energy-storage devices: Design consideration and recent progress. Adv. Mater. 2014;26:4763–4782. doi: 10.1002/adma.201400910. PubMed DOI

Scalia A., Bella F., Lamberti A., Bianco S., Gerbaldi C., Tresso E., Pirri C.F. A flexible and portable powerpack by solid-state supercapacitor and dye-sensitized solar cell integration. J. Power Sources. 2017;359:311–321. doi: 10.1016/j.jpowsour.2017.05.072. DOI

Wang G., Zhang L., Zhang J. A review of electrode materials for electrochemical supercapacitors. Chem. Soc. Rev. 2012;41:797–828. doi: 10.1039/C1CS15060J. PubMed DOI

Zhong C., Deng Y., Hu W., Qiao J., Zhang L., Zhang J. A review of electrolyte materials and compositions for electrochemical supercapacitors. Chem. Soc. Rev. 2015;44:7484–7539. doi: 10.1039/C5CS00303B. PubMed DOI

Abdallah T., Lemordant D., Claude-Montigny B. Are room temperature ionic liquids able to improve the safety of supercapacitors organic electrolytes without degrading the performances? J. Power Sources. 2012;201:353–359. doi: 10.1016/j.jpowsour.2011.10.115. DOI

Chang Z., Yang Y., Li M., Wang X., Wu Y. Green energy storage chemistries based on neutral aqueous electrolytes. J. Mater. Chem. A. 2014;2:10739–10755. doi: 10.1039/C4TA00565A. DOI

Virya A., Lian K. Li2SO4-polyacrylamide polymer electrolytes for 2.0V solid symmetric supercapacitors. Electrochem. Commun. 2017;81:52–55. doi: 10.1016/j.elecom.2017.06.003. DOI

Dai Z., Peng C., Chae J.H., Ng K.C., Chen G.Z. Cell voltage versus electrode potential range in aqueous supercapacitors. Sci. Rep. 2015;5:9854. doi: 10.1038/srep09854. PubMed DOI PMC

Gao Q., Demarconnay L., Raymundo-Piñero E., Béguin F. Exploring the large voltage range of carbon/carbon supercapacitors in aqueous lithium sulfate electrolyte. Energy Environ. Sci. 2012;5:9611. doi: 10.1039/c2ee22284a. DOI

Long J.W., Bélanger D., Brousse T., Sugimoto W., Sassin M.B., Crosnier O. Asymmetric electrochemical capacitors—Stretching the limits of aqueous electrolytes. MRS Bull. 2011;36:513–522. doi: 10.1557/mrs.2011.137. DOI

Khomenko V., Raymundo-Piñero E., Frackowiak E., Béguin F. High-voltage asymmetric supercapacitors operating in aqueous electrolyte. Appl. Phys. A. 2005;82:567–573. doi: 10.1007/s00339-005-3397-8. DOI

Yan J., Fan Z., Sun W., Ning G., Wei T., Zhang Q., Zhang R., Zhi L., Wei F. Advanced Asymmetric Supercapacitors Based on Ni(OH)2/Graphene and Porous Graphene Electrodes with High Energy Density. Adv. Funct. Mater. 2012;22:2632–2641. doi: 10.1002/adfm.201102839. DOI

Qu Q., Zhang P., Wang B., Chen Y., Tian S., Wu Y., Holze R. Electrochemical performance of MnO2 nanorods in neutral aqueous electrolytes as a cathode for asymmetric supercapacitors. J. Phys. Chem. C. 2009;113:14020–14027. doi: 10.1021/jp8113094. DOI

Niu Z., Zhang L., Liu L., Zhu B., Dong H., Chen X. All-solid-state flexible ultrathin micro-supercapacitors based on graphene. Adv. Mater. 2013;25:4035–4042. doi: 10.1002/adma.201301332. PubMed DOI

Peng X., Peng L., Wu C., Xie Y. Two dimensional nanomaterials for flexible supercapacitors. Chem. Soc. Rev. 2014;43:3303–3323. doi: 10.1039/c3cs60407a. PubMed DOI

Wen L., Li F., Cheng H.-M. Carbon nanotubes and graphene for flexible electrochemical energy storage: From materials to devices. Adv. Mater. 2016;28:4306–4337. doi: 10.1002/adma.201504225. PubMed DOI

Zhang H., Qiao Y., Lu Z. Fully printed ultraflexible supercapacitor supported by a single-textile substrate. ACS Appl. Mater. Interfaces. 2016;8:32317–32323. doi: 10.1021/acsami.6b11172. PubMed DOI

Shao Y., El-Kady M.F., Wang L.J., Zhang Q., Li Y., Wang H., Mousavi M.F., Kaner R.B. Graphene-based materials for flexible supercapacitors. Chem. Soc. Rev. 2015;44:3639–3665. doi: 10.1039/C4CS00316K. PubMed DOI

Peng L., Peng X., Liu B., Wu C., Xie Y., Yu G. Ultrathin two-dimensional MnO2/graphene hybrid nanostructures for high-performance, flexible planar supercapacitors. Nano Lett. 2013;13:2151–2157. doi: 10.1021/nl400600x. PubMed DOI

Zhao M.Q., Ren C.E., Ling Z., Lukatskaya M.R., Zhang C., Van Aken K.L., Barsoum M.W., Gogotsi Y. Flexible MXene/carbon nanotube composite paper with high volumetric capacitance. Adv. Mater. 2015;27:339–345. doi: 10.1002/adma.201404140. PubMed DOI

Wu C., Lu X., Peng L., Xu K., Peng X., Huang J., Yu G., Xie Y. Two-dimensional vanadyl phosphate ultrathin nanosheets for high energy density and flexible pseudocapacitors. Nat. Commun. 2013;4:2431. doi: 10.1038/ncomms3431. PubMed DOI

Wei W., Cui X., Chen W., Ivey D.G. Manganese oxide-based materials as electrochemical supercapacitor electrodes. Chem. Soc. Rev. 2011;40:1697–1721. doi: 10.1039/C0CS00127A. PubMed DOI

Xiong P., Ma R., Sakai N., Bai X., Li S., Sasaki T. Redox Active Cation Intercalation/Deintercalation in Two-dimensional layered MnO2 nanostructures for high-rate electrochemical energy storage. ACS Appl. Mater. Interfaces. 2017;9:6282–6291. doi: 10.1021/acsami.6b14612. PubMed DOI

Devaraj S., Munichandraiah N. Effect of crystallographic structure of MnO2 on its electrochemical capacitance properties. J. Phys. Chem. C. 2008;112:4406–4417. doi: 10.1021/jp7108785. DOI

Omomo Y., Sasaki T., Zhou L., Watanabe M. Redoxable nanosheet crystallites of MnO2 derived via delamination of a layered manganese oxide. J. Am. Chem. Soc. 2003;125:3568–3575. doi: 10.1021/ja021364p. PubMed DOI

Athouël L., Moser F., Dugas R., Crosnier O., Bélanger D., Brousse T. Variation of the MnO2 birnessite structure upon charge/discharge in an electrochemical supercapacitor electrode in aqueous Na2SO4 electrolyte. J. Phys. Chem. C. 2008;112:7270–7277. doi: 10.1021/jp0773029. DOI

Huang M., Zhang Y., Li F., Zhang L., Ruoff R.S., Wen Z., Liu Q. Self-assembly of mesoporous nanotubes assembled from interwoven ultrathin birnessite-type MnO2 nanosheets for asymmetric supercapacitors. Sci. Rep. 2014;4:3878. doi: 10.1038/srep03878. PubMed DOI PMC

Cao J., Li X., Wang Y., Walsh F.C., Ouyang J.-H., Jia D., Zhou Y. Materials and fabrication of electrode scaffolds for deposition of MnO2 and their true performance in supercapacitors. J. Power Sources. 2015;293:657–674. doi: 10.1016/j.jpowsour.2015.05.115. DOI

Ko Y., Kwon M., Bae W.K., Lee B., Lee S.W., Cho J. Flexible supercapacitor electrodes based on real metal-like cellulose papers. Nat. Commun. 2017;8:536. doi: 10.1038/s41467-017-00550-3. PubMed DOI PMC

Kuila T., Mishra A.K., Khanra P., Kim N.H., Lee J.H. Recent advances in the efficient reduction of graphene oxide and its application as energy storage electrode materials. Nanoscale. 2013;5:52–71. doi: 10.1039/C2NR32703A. PubMed DOI

Lee J.W., Hall A.S., Kim J.-D., Mallouk T.E. A Facile and Template-free hydrothermal synthesis of Mn3O4 nanorods on graphene sheets for supercapacitor electrodes with long cycle stability. Chem. Mater. 2012;24:1158–1164. doi: 10.1021/cm203697w. DOI

Gao H., Xiao F., Ching C.B., Duan H. Flexible all-solid-state asymmetric supercapacitors based on free-standing carbon nanotube/graphene and Mn3O4 nanoparticle/graphene paper electrodes. ACS Appl. Mater. Interfaces. 2012;4:7020–7026. doi: 10.1021/am302280b. PubMed DOI

Saravanakumar B., Purushothaman K.K., Muralidharan G. Fabrication of two-dimensional reduced graphene oxide supported V2O5 networks and their application in supercapacitors. Mater. Chem. Phys. 2016;170(Suppl. C):266–275. doi: 10.1016/j.matchemphys.2015.12.051. DOI

Cai M., Thorpe D., Adamson D.H., Schniepp H.C. Methods of graphite exfoliation. J. Mater. Chem. 2012;22:24992. doi: 10.1039/c2jm34517j. DOI

Xiang C., Young C.C., Wang X., Yan Z., Hwang C.-C., Cerioti G., Lin J., Kono J., Pasquali M., Tour J.M. Large flake graphene oxide fibers with unconventional 100% knot efficiency and highly aligned small flake graphene oxide fibers. Adv. Mater. 2013;25:4592–4597. doi: 10.1002/adma.201301065. PubMed DOI

Wang X., Bai H., Shi G. Size fractionation of graphene oxide sheets by pH-assisted selective sedimentation. J. Am. Chem. Soc. 2011;133:6338–6342. doi: 10.1021/ja200218y. PubMed DOI

Du P., Liu H.C., Yi C., Wang K., Gong X. Polyaniline-modified oriented graphene hydrogel film as the free-standing electrode for flexible solid-state supercapacitors. ACS Appl. Mater. Interfaces. 2015;7:23932–23940. doi: 10.1021/acsami.5b06261. PubMed DOI

Xu Y., Lin Z., Huang X., Liu Y., Huang Y., Duan X. Flexible solid-state supercapacitors based on three-dimensional graphene hydrogel films. ACS Nano. 2013;7:4042–4049. doi: 10.1021/nn4000836. PubMed DOI

Wang Y., Yang X., Qiu L., Li D. Revisiting the capacitance of polyaniline by using graphene hydrogel films as a substrate: The importance of nano-architecturing. Energy Environ. Sci. 2013;6:477–481. doi: 10.1039/C2EE24018A. DOI

Lee Y.R., Kim I.Y., Kim T.W., Lee J.M., Hwang S.J. Mixed colloidal suspensions of reduced graphene oxide and layered metal oxide nanosheets: Useful precursors for the porous nanocomposites and hybrid films of graphene/metal oxide. Chem. Eur. J. 2012;18:2263–2271. doi: 10.1002/chem.201102646. PubMed DOI

Tang Q., Sun M., Yu S., Wang G. Preparation and supercapacitance performance of manganese oxide nanosheets/graphene/carbon nanotubes ternary composite film. Electrochim. Acta. 2014;125:488–496. doi: 10.1016/j.electacta.2014.01.139. DOI

Kai K., Yoshida Y., Kageyama H., Saito G., Ishigaki T., Furukawa Y., Kawamata J. Room-temperature synthesis of manganese oxide monosheets. J. Am. Chem. Soc. 2008;130:15938–15943. doi: 10.1021/ja804503f. PubMed DOI

Li D., Muller M.B., Gilje S., Kaner R.B., Wallace G.G. Processable aqueous dispersions of graphene nanosheets. Nat. Nanotechnol. 2008;3:101–105. doi: 10.1038/nnano.2007.451. PubMed DOI

Eigler S., Enzelberger-Heim M., Grimm S., Hofmann P., Kroener W., Geworski A., Dotzer C., Rockert M., Xiao J., Papp C., et al. Wet chemical synthesis of graphene. Adv. Mater. 2013;25:3583–3587. doi: 10.1002/adma.201300155. PubMed DOI

Gao H., Lian K. Proton-conducting polymer electrolytes and their applications in solid supercapacitors: A review. RSC Adv. 2014;4:33091–33113. doi: 10.1039/C4RA05151C. DOI

Lv X., Li G., Li D., Huang F., Liu W., Wei Q. A new method to prepare no-binder, integral electrodes-separator, asymmetric all-solid-state flexible supercapacitor derived from bacterial cellulose. J. Phys. Chem. Solids. 2017;110:202–210. doi: 10.1016/j.jpcs.2017.06.017. DOI

Sacco A., Bella F., De La Pierre S., Castellino M., Bianco S., Bongiovanni R., Pirri C.F. Electrodes/Electrolyte Interfaces in the Presence of a Surface-Modified Photopolymer Electrolyte: Application in Dye-Sensitized Solar Cells. ChemPhysChem. 2015;16:960–969. doi: 10.1002/cphc.201402891. PubMed DOI

Brousse T., Taberna P.-L., Crosnier O., Dugas R., Guillemet P., Scudeller Y., Zhou Y., Favier F., Bélanger D., Simon P. Long-term cycling behavior of asymmetric activated carbon/MnO2 aqueous electrochemical supercapacitor. J. Power Sources. 2007;173:633–641. doi: 10.1016/j.jpowsour.2007.04.074. DOI

Gao H., Xiao F., Ching C.B., Duan H. High-performance asymmetric supercapacitor based on graphene hydrogel and nanostructured MnO2. ACS Appl. Mater. Interfaces. 2012;4:2801–2810. doi: 10.1021/am300455d. PubMed DOI

El-Kady M.F., Ihns M., Li M., Hwang J.Y., Mousavi M.F., Chaney L., Lech A.T., Kaner R.B. Engineering three-dimensional hybrid supercapacitors and microsupercapacitors for high-performance integrated energy storage. Proc. Natl. Acad. Sci. USA. 2015;112:4233–4238. doi: 10.1073/pnas.1420398112. PubMed DOI PMC

Dong L., Xu C., Li Y., Huang Z.-H., Kang F., Yang Q.-H., Zhao X. Flexible electrodes and supercapacitors for wearable energy storage: A review by category. J. Mater. Chem. A. 2016;4:4659–4685. doi: 10.1039/C5TA10582J. DOI

Lokhande C.D., Dubal D.P., Joo O.-S. Metal oxide thin film based supercapacitors. Curr. Appl. Phys. 2011;11:255–270. doi: 10.1016/j.cap.2010.12.001. DOI

Hsu Y.K., Chen Y.C., Lin Y.G., Chen L.C., Chen K.H. Reversible phase transformation of MnO2 nanosheets in an electrochemical capacitor investigated by in situ Raman spectroscopy. Chem. Commun. 2011;47:1252–1254. doi: 10.1039/C0CC03902K. PubMed DOI

Wei W., Cui X., Chen W., Ivey D.G. Electrochemical cyclability mechanism for MnO2 electrodes utilized as electrochemical supercapacitors. J. Power Sources. 2009;186:543–550. doi: 10.1016/j.jpowsour.2008.10.058. DOI

Koo M., Park K.-I., Lee S.H., Suh M., Jeon D.Y., Choi J.W., Kang K., Lee K.J. Bendable inorganic thin-film battery for fully flexible electronic systems. Nano Lett. 2012;12:4810–4816. doi: 10.1021/nl302254v. PubMed DOI

Suo Z., Ma E.Y., Gleskova H., Wagner S. Mechanics of rollable and foldable film-on-foil electronics. Appl. Phys. Lett. 1999;74:1177–1179. doi: 10.1063/1.123478. DOI

Gleskova H., Cheng I.C., Wagner S., Suo Z. Mechanical theory of the film-on-substrate-foil structure: Curvature and overlay alignment in amorphous silicon thin-film devices fabricated on free-standing foil substrates. In: Wong W.S., Salleo A., editors. Flexible Electronics: Materials and Applications. Springer Science & Business Media; New York, NY, USA: 2009. pp. 29–50.