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The ever-increasing demand for powering wearable electronics, energy concern, and climate crisis, arouse attention for developing energy storage systems with high energy and power density, long cycling life, and excellent mechanical flexibility. Herein, we demonstrate a hierarchical 3D electrode for high-performance flexible supercapacitors, in which metallic molybdenum disulfide (MoS 2) nanosheets are uniformly deposited on the surface of carbon nanocones (CNC) grown on carbon cloths (CC), yielding CC-CNC@MoS 2. The 3D CC-CNC substrate provides a large surface for high mass loading of MoS 2 , a high pathway for fast electron transfers as well as the porous structure for efficient electrolyte ion diffusion to access active materials. Also, the layered structure of metallic MoS 2 nanosheets enables large amounts of active sites and facilitates ion transport as well. Benefitting from the rational nanostructure design, the assembled quasi-solid-state supercapacitor yielded a maximum energy density of 0.016 mWh cm−2 and a peak power density of 8.3 mW cm−2, and ultra-high cycling stability over 10,000 cycles, outperforming many recently reported flexible supercapacitors. Furthermore, the excellent mechanical properties of both CC-CNC substrates and MoS 2 nanosheets endow the resulting quasi-solid-state supercapacitors with compelling flexibility for wearable electronics. Finally, an energy storage unit fabricated from the supercapacitors could light an LED, demonstrating its great application potential in wearable electronics. Facile synthesis of hierarchical 3D carbon nanocones/metallic MoS 2 electrodes for high-performance flexible supercapacitors. [Display omitted] • 3D carbon nanocones/M − MoS 2 enables fast electron transfer, efficient ion diffusion. • Metallic 1T MoS 2 has good electrical conductivity & hydrophilicity. • Metallic 1T MoS 2 provides abundant active sites for large charge storage. • Quasi-solid-state supercapacitors delivered excellent performance & flexibility. [ABSTRACT FROM AUTHOR]

Typical desalination techniques, such as reverse osmosis, distillation, capacitive deionization, and battery desalination, require lots of electrical or thermal energy consumption. As a new emerging desalination technique, the solar-driven photoelectrochemical desalination (SD-PED) technology by using sustainable solar energy to remove salt ions without any external bias has been developed and caused much attention. The SD-PED technique with dual functions of desalination and photoelectric conversion driven by sunlight has demonstrated that a high initial photocurrent up to 9.5 mA can be obtained in the existing work with 99.95% salt removal rate. However, some limitations are remained such as the fast decline of photocurrent, difficulty in the seawater desalination, the long-term stability of system etc. To better understand this new desalination technique, herein, we comprehensively review and discuss the status of SD-PED system for the first time, including the device configuration, influencing factors and the active involved materials of solar absorbers and redox electrolyte species. Further, the strategies to improve the performance of long-term stability desalination are summarized, such as the configuration connection in series or parallel, the combination of photoanode and photocathode, the photosensitive material with wide solar absorption. At last, the challenge and prospect are further guided for the future development of SD-PED technology, which are expected to realize the commercialization. A new type of electricity-free solar-driven electrochemical desalination technique was proposed very recently which could achieve continuous desalination by circulating the redox flow electrolyte. This review comprehensively describes the recent development of SD-PED technique to determine its advantages and disadvantages with guiding further technology development. Followed by discussion the mechanism, device configuration, solar absorber materials, redox electrolyte species and influencing factors of SD-PED system. Finally, state the challenges, discussions for future work, conclusions and perspectives in the last section. The SD-PED technique is a promising solution to the worldwide energy and water shortage crisis. [Display omitted] • The SD-PED technology was reviewed for the first time. • Development and desalting mechanisms of SD-PED technology was summarized. • The configurations, materials and performance influence factors were analyzed. • The challenges & perspectives are guided for the future development of SD-PED. [ABSTRACT FROM AUTHOR]