Graphical Abstract
![](https://wqketang.oss-cn-beijing.aliyuncs.com/unzip/large-zip/zip-69492bde-594b-4866-8077-256e9eef0893/5201/files/5201-TOC.jpg?Expires=1725756546&OSSAccessKeyId=STS.NSssK71aLjDMY9SbRgGRGskMT&Signature=VX8yQeBqlY3CsK%2BZZMjyjI8kXDU%3D&security-token=CAISywJ1q6Ft5B2yfSjIr5DGOPGD3L5t3YamWx%2FihlIyS91rnK7mtjz2IHtKenhsBOsbtfk1mG5W5%2FgZlqJ9SptIAEfJa9d99Myjb%2F9FltCT1fau5Jko1beHewHKeTOZsebWZ%2BLmNqC%2FHt6md1HDkAJq3LL%2Bbk%2FMdle5MJqP%2B%2FUFB5ZtKWveVzddA8pMLQZPsdITMWCrVcygKRn3mGHdfiEK00he8TouufTinpHMskGA1Aell7Mvyt6vcsT%2BXa5FJ4xiVtq55utye5fa3TRYgxowr%2Fwo0v0YpGya5YzHXwcPskvdKZbo78UqLQlla6w%2BGqFJqvPxr%2Fp8t%2Fx5fWJKAezhVgs8cVM8JOjIqKOscIsixo262SmqFV55c8Fdm%2BgUooJVgIMhTnduUfAPJAGOxzJitP%2BUVGGphr60TEnBL4rB5MUctfzRpwT64j3UTzDnGoABhFRSspTLrn9GrEN9pQYzC6eepGdfWDQh3fr5hA1VnwVUJMCz%2BNQEDWKceF%2FnEjWVMtfbvqYxuyhSCmIMMyh5bEREEKEiD%2BFVv4ZfsqnV7hQy5w6HhIkN8kZzP6L0zPvPgkBLOtdMDeDxhf8dVPrCSG4etXHjxcwUaRVb3ZR7Yu8gAA%3D%3D)
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Herein, we prepare the unique hierarchical polypyrrole@cobalt sulfide (PPy-hs@CoS) hollow sphere-based nanofilms as interdigitated electrodes for flexible on-chip micro-supercapacitors (MSC). Benefiting from the excellent flexibility and high electrical conductivity of PPy-hs combined with the great electrochemical activity of CoS, such PPy-hs@CoS composite material can not only inhibit the volume expansion of PPy but also promote the diffusion of the electrolyte ions. The PPy-hs@CoS film-based electrode delivers a greatly improved specific capacitance and small resistance. Density functional theory calculations infer that OH− prefers to bind to PPy on CoS@PPy and confirms the synergistic effect of each component for enhanced reaction kinetics. A quasi-solid-state on-chip flexible asymmetric MSC based on PPy-hs@CoS and activated carbon (AC) microelectrodes exhibits large areal-specific capacitance (131.9 mF/cm2 at 0.3 mA/cm2), ultrahigh energy density (0.041 mWh/cm2@0.224 mW/cm2 and 25.6 mWh/cm3@140.6 mW/cm3), and long cycle lifespan. We demonstrate the possibility to scale up the PPy-hs@CoS nanofilm microelectrode by arranging two of our asymmetric MSC in series and parallel connections, which respectively increase the output voltage and current. A self-charging system by connecting our asymmetric MSCs with a piece of commercial solar cells is developed as a potential possible mode for future highly durable and high-voltage integrated electronics.
Feng, X.; Shi, X. Y.; Ning, J.; Wang, D.; Zhang, J. C.; Hao, Y.; Wu, Z. S. Recent advances in micro-supercapacitors for AC line-filtering performance: From fundamental models to emerging applications. eScience 2021, 1, 124–140.
Peng, M. K.; Wang, L.; Li, L. B.; Peng, Z. Y.; Tang, X. N.; Hu, T.; Yuan, K.; Chen, Y. W. Molecular crowding agents engineered to make bioinspired electrolytes for high-voltage aqueous supercapacitors. eScience 2021, 1, 83–90.
Cao, S.; Zhang, H. C.; Zhao, Y. X.; Zhao, Y. L. Pillararene/calixarene-based systems for battery and supercapacitor applications. eScience 2021, 1, 28–43.
Zhang, M.; Cao, J.; Wang, Y.; Song, J.; Jiang, T. C.; Zhang, Y. Y.; Si, W. M.; Li, X. W.; Meng, B.; Wen. Gu. W. Electrolyte-mediated dense integration of graphene-MXene films for high volumetric capacitance flexible supercapacitors. Nano Res. 2021, 14, 699–706.
Li, Z. J.; Dai, J.; Li, Y. R.; Sun, C. L.; Meng, A. L.; Cheng, R. F.; Zhao, J.; Hu, M. M. Wang. X. H. Intercalation−deintercalation design in MXenes for high-performance supercapacitors. Nano Res. 2022, 15, 3213–3221.
Guo, R.; Han, X. Y.; Yuan, P.; He, X. X.; Li, Q.; Sun, J.; Dang, L. Q.; Liu, Z. H.; Zhang, Y. T.; Lei. Z. B. Filling Ti3C2Tx nanosheets into melamine foam towards a highly compressible all-in-one supercapacitor. Nano Res. 2022, 15, 3254–3263.
Yu, D. S.; Goh, K.; Wang, H.; Wei, L.; Jiang, W. C.; Zhang, Q.; Dai, L. M.; Chen, Y. Scalable synthesis of hierarchically structured carbon nanotube-graphene fibres for capacitive energy storage. Nat. Nanotechnol. 2014, 9, 555–562.
Kamboj, N.; Purkait, T.; Das, M.; Sarkar, S.; Hazra, K. S.; Dey, R. S. Ultralong cycle life and outstanding capacitive performance of a 10.8 V metal free micro-supercapacitor with highly conducting and robust laser-irradiated graphene for an integrated storage device. Energy Environ. Sci. 2019, 12, 2507–2517.
Tan, Z.-L.; Wei, J.-X.; Liu, Y.; Zaman, F. U.; Rehman, W.; Hou, L.-R.; Yuan, C.-Z. V2CTx MXene and its derivatives: Synthesis and recent progress in electrochemical energy storage applications. Rare Metals 2022, 41, 775–797.
Chen, M. F.; Chen, J. Z.; Zhou, W. J.; Xu, J. L.; Wong, C. P. High-performance flexible and self-healable quasi-solid-state zinc-ion hybrid supercapacitor based on borax-crosslinked polyvinyl alcohol/nanocellulose hydrogel electrolyte. J. Mater. Chem. A 2019, 7, 26524–26532.
Jiang, S.-H.; Ding, J.; Wang, R.-H.; Chen, F.-Y.; Sun, J.; Deng, Y.-X.; Li, X.-L. Solvothermal-induced construction of ultra-tiny Fe2O3 nanoparticles/graphene hydrogels as binder-free high-capacitance anode for supercapacitors. Rare Metals 2021, 40, 3520–3530.
Zhang, P. P.; Wang, F. X.; Yang, S.; Wang, G.; Yu, M. H.; Feng, X. L. Flexible in-plane micro-supercapacitors: Progresses and challenges in fabrication and applications. Energy Storage Mater. 2020, 28, 160–187.
Qiu, Y. T.; Hou, M. Z.; Gao, J. C.; Zhai, H. L.; Liu, H. M.; Jin, M. M.; Liu, X.; Lai, L. F. One-step synthesis of monodispersed mesoporous carbon nanospheres for high-performance flexible quasi-solid-state micro-supercapacitors. Small 2019, 15, 1903836.
Rong, Y. X.; Chen, Y.; Zheng, J. H.; Zhao, Y.; Li, Q. P. Development of high performance alpha-Co(OH)2/reduced graphene oxide microfilm for flexible in-sandwich and planar micro-supercapacitors. J. Colloid Interface Sci. 2021, 598, 1–13.
Zhang, Y.; Ji, T. X.; Hou, S. H.; Zhang, L. F.; Shi, Y. H.; Zhao, J. X.; Xu, X. H. All-printed solid-state substrate-versatile and high-performance micro-supercapacitors for in situ fabricated transferable and wearable energy storage via multi-material 3D printing. J. Power Sources 2018, 403, 109–117.
Huang, T. Q.; Cai, S. Y.; Chen, H.; Jiang, Y. Q.; Wang, S. Y.; Gao, C. Continuous fabrication of the graphene-confined polypyrrole film for cycling stable supercapacitors. J. Mater. Chem. A 2017, 5, 8255–8260.
Huang, Y.; Li, H. F.; Wang, Z. F.; Zhu, M. S.; Pei, Z. X.; Xue, Q.; Huang, Y.; Zhi, C. Y. Nanostructured polypyrrole as a flexible electrode material of supercapacitor. Nano Energy 2016, 22, 422–438.
Zhao, C.; Jia, X. T.; Shu, K. W.; Yu, C. C.; Wallace, G. G.; Wang, C. Y. Conducting polymer composites for unconventional solid-state supercapacitors. J. Mater. Chem. A 2020, 8, 4677–4699.
Liu, W. J.; Zhao, Y.; Zheng, J. H.; Jin, D. Y.; Wang, Y. Q.; Lian, J. B.; Yang, S. L.; Li, G. C.; Bu, Y. F.; Qiao, F. Heterogeneous cobalt polysulfide leaf-like array/carbon nanofiber composites derived from zeolite imidazole framework for advanced asymmetric supercapacitors. J. Colloid Interface Sci. 2022, 606, 728–735.
Snook, G. A.; Kao, P.; Best, A. S. Conducting-polymer-based supercapacitor devices and electrodes. J. Power Sources 2011, 196, 1–12.
Zhai, Z. B.; Yan, W.; Dong, L.; Wang, J. Y.; Chen, C. H.; Lian, J.; Wang, X. M.; Xia, D. G.; Zhang, J. J. Multi-dimensional materials with layered structures for supercapacitors: Advanced synthesis, supercapacitor performance and functional mechanism. Nano Energy 2020, 78, 105193.
Teng, X. L.; Sun, X. T.; Guan, L.; Hu, H.; Wu, M. B. Self-supported transition metal oxide electrodes for electrochemical energy storage. Tungsten 2020, 2, 337–361.
Deng, Z. W.; Chen, M.; Gu, G. X.; Wu, L. M. A facile method to fabricate ZnO hollow spheres and their photocatalytic property. J. Phys. Chem. B 2008, 112, 16–22.
Osman, S.; Senthil, R. A.; Pan, J. Q.; Sun, Y. Z. A novel coral structured porous-like amorphous carbon derived from zinc-based fluorinated metal-organic framework as superior cathode material for high performance supercapacitors. J. Power Sources 2019, 414, 401–411.
Liu, S.; Zeng, Y. X.; Zhang, M.; Xie, S. L.; Tong, Y. X.; Cheng, F. L.; Lu, X. H. Binder-free WS2 nanosheets with enhanced crystallinity as a stable negative electrode for flexible asymmetric supercapacitors. J. Mater. Chem. A 2017, 5, 21460–21466.
Liu, H.; Cui, G. Z.; Li, L.; Zhang, Z.; Lv, X. L.; Wang, X. X. Polypyrrole chains decorated on CoS spheres: A core–shell like heterostructure for high-performance microwave absorption. Nanomaterials 2020, 10, 166.
Park, H.; Kim, J. W.; Hong, S. Y.; Lee, G.; Kim, D. S.; Oh, J. H.; Jin, S. W.; Jeong, Y. R.; Oh, S. Y.; Yun, J. Y. et al. Microporous polypyrrole-coated graphene foam for high-performance multifunctional sensors and flexible supercapacitors. Adv. Funct. Mater. 2018, 28, 1707013.
Huang, L.; Yao, X.; Yuan, L. Y.; Yao, B.; Gao, X.; Wan, J.; Zhou, P. P.; Xu, M.; Wu, J. B.; Yu, H. M. et al. 4-Butylbenzenesulfonate modified polypyrrole paper for supercapacitor with exceptional cycling stability. Energy Storage Mater 2018, 12, 191–196.
Mohammadi, A.; Arsalani, N.; Tabrizi, A. G.; Moosavifard, S. E.; Naqshbandi, Z.; Ghadimi, L. S. Engineering rGO-CNT wrapped Co3S4 nanocomposites for high-performance asymmetric supercapacitors. Chem. Eng. J. 2018, 334, 66–80.
Huo, J. H.; Wu, J. H.; Zheng, M.; Tu, Y. G.; Lan, Z. A transparent cobalt sulfide/reduced graphene oxide nanostructure counter electrode for high efficient dye-sensitized solar cells. Electrochim. Acta 2016, 187, 210–217.
Zheng, Y. Y.; Xu, J.; Yang, X. S.; Zhang, Y. J.; Shang, Y. Y.; Hu, X. Y. Decoration NiCo2S4 nanoflakes onto PPy nanotubes as core–shell heterostructure material for high-performance asymmetric supercapacitor. Chem. Eng. J. 2018, 333, 111–121.
Song, X. M.; Tan, L. C.; Wang, X. L.; Zhu, L.; Yi, X. Q.; Dong, Q. Synthesis of CoS@rGO composites with excellent electrochemical performance for supercapacitors. J. Electroanal. Chem. 2017, 794, 132–138.
Subramani, K.; Sudhan, N.; Divya, R.; Sathish, M. All-solid-state asymmetric supercapacitors based on cobalt hexacyanoferrate-derived CoS and activated carbon. RSC Adv. 2017, 7, 6648–6659.
Liu, Y.; Guo, S. J.; Zhang, W.; Kong, W.; Wang, Z. D.; Yan, W. J.; Fan, H. L.; Hao, X. G.; Guan, G. Q. Three-dimensional interconnected cobalt sulfide foam: Controllable synthesis and application in supercapacitor. Electrochim. Acta 2019, 317, 551–561.
Zhao, Y.; Zheng, J. H.; Yuan, M.; Wang, Y. Q.; Liu, W. J.; Yang, S. L.; Li, G. C.; Lian, J. B.; Bu, Y. F. Boosting the energy density of iron-cobalt oxide based hybrid supercapacitors by redox-additive electrolytes. J. Alloys Compd. 2021, 885, 160886.
Deng, T.; Lu, Y.; Zhang, W.; Sui, M. L.; Shi, X. Y.; Wang, D.; Zheng, W. T. Inverted design for high-performance supercapacitor via Co(OH)2-derived highly oriented MOF electrodes. Adv. Energy Mater. 2018, 8, 1702294.
Wang, H. X.; Qiu, F.; Lu, C. B.; Zhu, J. H.; Ke, C. C.; Han, S.; Zhuang, X. D. A terpyridine-Fe2+-based coordination polymer film for on-chip micro-supercapacitor with AC line-filtering performance. Polymers 2021, 13, 1002.
Li, L.; Zhang, J. B.; Peng, Z. W.; Li, Y. L.; Gao, C. T.; Ji, Y.; Ye, R. Q.; Kim, N. D.; Zhong, Q. F.; Yang, Y. et al. High-performance pseudocapacitive microsupercapacitors from laser-induced graphene. Adv. Mater. 2016, 28, 838–845.
Yang, W.; He, L.; Tian, X. C.; Yan, M. Y.; Yuan, H.; Liao, X. B.; Meng, J. S.; Hao, Z. M.; Mai, L. Carbon-MEMS-based alternating stacked MoS2@rGO-CNT micro-supercapacitor with high capacitance and energy density. Small 2017, 13, 1700639.
Feng, J.; Sun, X.; Wu, C. Z.; Peng, L. L.; Lin, C. W.; Hu, S. L.; Yang, J. L.; Xie, Y. Metallic few-layered VS2 ultrathin nanosheets: High two-dimensional conductivity for in-plane supercapacitors. J. Am. Chem. Soc. 2011, 133, 17832–17838.
Wu, Z. S.; Zheng, Y. J.; Zheng, S. H.; Wang, S.; Sun, C. L.; Parvez, K.; Ikeda, T.; Bao, X. H.; Müllen, K.; Feng, X. L. Stacked-layer heterostructure films of 2D thiophene nanosheets and graphene for high-rate all-solid-state pseudocapacitors with enhanced volumetric capacitance. Adv. Mater. 2017, 29, 1602960.
Tahir, M.; He, L.; Yang, W.; Hong, X. F.; Haider, W. A.; Tang, H.; Zhu, Z.; Owusu, K. A.; Mai, L. Boosting the electrochemical performance and reliability of conducting polymer microelectrode via intermediate graphene for on-chip asymmetric micro-supercapacitor. J. Energy Chem. 2020, 49, 224–232.
Tian, H.; Qin, J. Q.; Hou, D.; Li, Q.; Li, C.; Wu, Z. S.; Mai, Y. General interfacial self-assembly engineering for patterning two-dimensional polymers with cylindrical mesopores on graphene. Angew. Chem., Int. Ed. 2019, 58, 10173–10178.
Liu, X. J.; Qian, T.; Xu, N.; Zhou, J. Q.; Guo, J.; Yan, C. L. Preparation of on chip, flexible supercapacitor with high performance based on electrophoretic deposition of reduced graphene oxide/polypyrrole composites. Carbon 2015, 92, 348–353.
Zheng, S. H.; Wang, S.; Dong, Y. F.; Zhou, F.; Qin, J. Q.; Wang, X.; Su, F.; Sun, C. L.; Wu, Z. S.; Cheng, H. M. et al. All-solid-state planar sodium-ion microcapacitors with multidirectional fast ion diffusion pathways. Adv. Sci. 2019, 6, 1902147.