Ordered mesoporous carbon (OMC) is considered one of the most promising materials for electric double layer capacitors (EDLC) given its low‐cost, high specific surface area, and easily accessed ordered pore channels. However, pristine OMC electrode suffers from poor electrical conductivity and mechanical flexibility, whose specific capacitance and cycling stability is unsatisfactory in flexible devices. In this work, OMC is coated on the surface of highly conductive three‐dimensional graphene foam, serving as both charge collector and flexible substrate. Upon further decoration with silver nanowires (Ag NWs), the novel architecture of Ag NWs/3D‐graphene foam/OMC (Ag‐GF‐OMC) exhibits exceptional electrical conductivity (up to 762 S cm−1) and mechanical robustness. The Ag‐GF‐OMC electrodes in flexible supercapacitors reach a specific capacitance as high as 213 F g−1, a value five‐fold higher than that of the pristine OMC electrode. Moreover, these flexible electrodes also exhibit excellent long‐term stability with >90% capacitance retention over 10 000 cycles, as well as high energy and power density (4.5 Wh kg−1 and 5040 W kg−1, respectively). This study provides a new procedure to enhance the device performance of OMC based supercapacitors, which is a promising candidate for the application of flexible energy storage devices.

Lithium (Li) or zinc (Zn) metal anodes have attracted interest for battery research due to their high theoretical capacities and low redox potentials. However, uncontrollable dendrite growth, especially under high current (>4 mA cm−2), precludes reversable cycling in Li or Zn metal batteries with a high-loading (>4 mAh cm−2), precludes reversable cycling in Li or Zn metal batteries with high-loading (>4 mAh cm−2) cathode. We report a cation regulation mechanism to address this failure. Collagen hydrolysate coated on absorbed glass mat (CH@AGM) can simultaneously induce a deionization shock inside the separator and spread cations on the anode to promote uniform electrodeposition. Employing 24 mAh cm−2 cathodes, Li and Zn metal batteries with CH@AGM delivered 600 cycles with a Coulombic efficiency of 99.7%. In comparison, pristine Li and Zn metal batteries only survive for 10 and 100 cycles, respectively. This approach enabled 400 cycles in a 200 Ah-class Zn metal battery, which suggests a scalable method to achieve dendrite-free anodes in various batteries.

An ultrathin graphene artificial interphase stabilizes active material and conductive carbon in aqueous energy storage systems.

Rechargeable aqueous Zn-MnO 2 batteries are a promising candidate for large-scale energy storage systems due to their outstanding advantages, such as high energy density, high safety, low cost, and environmental friendliness. Considering the controversies surrounding the mechanism of this battery containing a mildly acidic electrolyte, the electrochemical behavior of this type of battery using β-MnO 2 as the cathode is systematically investigated. The results indicate that the reversible intercalation of Zn 2+ ions into MnO 2 is not likely to take place in the aqueous system. We conclude that it is the existence of the water molecule and its participation in the electrochemical reactions, for instance, the reversible insertion of proton into MnO 2 and the electrolysis of water, that makes the mechanism of aqueous Zn-MnO 2 batteries complicated. Besides, the capacity fading of this mildly acidic Zn-MnO 2 battery is assigned to the generation of the inert layer of Zn 4 SO 4 (OH) 6 •nH 2 O and the ZnMn 2 O 4 on the cathode via electrochemical conversion reactions, the dissolution of the active material during discharging, and the release of gases. When Mn 2+ ions are available in the electrolyte, they will be electrodeposited on the cathode during charging, and the kinetics of the electrochemical reactions of the electrode is improved, leading to the higher electrochemical performance of the battery.