Integrated Uniformly Microporous C₄N/Multi‐Walled Carbon Nanotubes Composite Toward Ultra‐Stable and Ultralow‐Temperature Proton Batteries

Abstract

Benefiting from the proton's small size and ultrahigh mobility in water, aqueous proton batteries are regarded as an attractive candidate for high‐power and ultralow‐temperature energy storage devices. Herein, a new‐type C4N polymer with uniform micropores and a large specific surface area is prepared by sulfuric acid‐catalyzed ketone amine condensation reaction and employed as the electrode of proton batteries. Multi‐walled carbon nanotubes (MWCNT) are introduced to induce the in situ growth of C4N, and reaped significantly enhanced porosity and conductivity, and thus better both room‐ and low‐temperature performance. When coupled with MnO2@Carbon fiber (MnO2@CF) cathode, MnO2@CF//C4N‐50% MWCNT full battery shows unprecedented cycle stability with a capacity retention of 98% after 11 000 cycles at 10 A g−1 and even 100% after 70 000 cycles at 20 A g−1. Additionally, a novel anti‐freezing electrolyte (5 m H2SO4 + 0.5 m MnSO4) is developed and showed a high ionic conductivity of 123.2 mS cm−1 at ‐70 °C. The resultant MnO2@CF//C4N‐50% MWCNT battery delivers a specific capacity of 110.5 mAh g−1 even at ‐70 °C at 1 A g−1, the highest in all reported proton batteries under the same conditions. This work is expected to offer a package solution for constructing high‐performance ultralow‐temperature aqueous proton batteries.

Steric hindrance modulation of hexaazatribenzanthraquinone isomers for high-capacity and wide-temperature-range aqueous proton battery

“…S30 , Video S1 and Table S6 ), beneficial for the following MnO 2 deposition. The MnO 2 @CF-KOH cathode was obtained according to our previous study [ 47 ]. The electrochemical properties, chemical information, and crystal structure of MnO 2 @CF-KOH as the cathode were evaluated using CV, XPS, and XRD in Figs S31 and S32 .…”

Electrolyte and Electrode–Electrolyte Interface for Proton Batteries: Insights and Challenges

“…[23][24][25] The small size of ions facilitates the rapid diffusion dynamics during the insertion and removal in electrodes, allowing energy storage devices to achieve high-power densities more easily. [26][27] The insertion of small ions reduces the structural strain of material, achieving long life cycles. [28][29] Compared to traditional metal ions, proton with lighter ion mass can alleviate the mass burden on battery, resulting in higher energy density for devices.…”

“…Proton with the lowest atomic mass and smallest ionic radius is an ideal charge carrier (Figure 1a). [23–25] The small size of ions facilitates the rapid diffusion dynamics during the insertion and removal in electrodes, allowing energy storage devices to achieve high‐power densities more easily [26–27] . The insertion of small ions reduces the structural strain of material, achieving long life cycles [28–29] .…”

Modifying Electronic Structure of Bismuth Telluride Through S Doping and Te Vacancy Engineering for Enhanced Zn‐Ion Storage Ability in Aqueous Zn‐proton Hybrid Ion Batteries

“…[ 12 ] Profiting from their light mass, small ionic radius, and fast kinetics, protons can achieve excellent rate and cycling performance. [ 13 ] Recently, bismuth chalcogenides have been investigated for Zn‐based energy‐storage devices. As confirmed by Peng et al., the Bi 2 Se 3 cathode displays a Zn 2+ /proton co‐insertion mechanism.…”