The porous structure composed of non-metal elements of covalent organic frameworks (COFs) contributes to a large surface area and multifunction, rendering COFs a brilliant material for energy storage. Unfortunately, the low conductivity of most COFs limits their application in batteries. Herein, we fabricate COF-derived nitrogen-doped porous carbon (NPC) using nitrogen-rich COF-JLU2 as precursors by a simple carbonization for potassium-ion batteries (PIBs) and aluminum (Al) batteries for the first time. The computational results suggest that NPC has an enhanced conductivity and optimized electron density distribution. NPC could overcome the low conductivity of COF and thus further optimize its electrochemical performance in PIBs and Al batteries. It displays an excellent stability even after 2500 cycles (as the anode for PIBs) and 30000 cycles (as the cathode for Al batteries) with a high Coulombic efficiency. This fascinating study may be extended in other COFs for energy storage applications.

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The structural and electronic properties of both Br substitution and vacancy structures of black orthorhombic CsPbI3 (γ‐CsPbI3) perovskite are investigated by carrying out first‐principle calculations in density functional theory (DFT). For mixed perovskites CsPb(I1−x Br x )3, x is 0.0, 0.25, 0.5, 0.75, and 1.0, respectively. The studies suggest that the III site should be preferentially substituted by Br atom rather than the II site and the structure becomes more stable with increasing Br content. These compounds are direct‐bandgap semiconductors in the range of 1.887−2.137 eV. Moreover, the vacancy changes the electroconductibility of γ‐CsPbI3. γ‐CsPbI3:VPb and γ‐CsPbI3:VI exhibit p‐type and n‐type conductivity, respectively. γ‐CsPbI3:VCs still is a semiconductor with a direct bandgap, which presents a slight decrease in electroconductibility due to the increase in bandgap. The calculated structural parameters show that both substitution and vacancy can induce structural distortion. Partial density of states (PDOS) suggests that the top of the valence band arises from hybridization of Pb s‐ and halogen p‐orbitals, whereas the bottom of the conduction band has predominantly Pb p‐orbitals for two kinds of crystal structures. These results provide strong support for developing high‐performance perovskite photovoltaic materials in optoelectronic devices.

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