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Highlights 1. A class of solvent-free covalent organic framework (COF) single-ion conductors (Li-COF@P) has been designed via ion–dipole interaction as opposed to traditional ion–ion interaction, promoting ion dissociation and Li+ migration through directional ionic channels. 2. The Li-COF@P enabled long cycle life (88.3% after 2000 cycles) in all-solid-state Li organic batteries (ASSLOBs) under ambient operating conditions, which outperformed those of previously reported ASSOLBs. 3. This Li-COF@P strategy holds promise as a viable alternative to the currently prevalent inorganic solid electrolytes.

In this paper, a compact quasi-Yagi antenna with embedded resistor-loaded arms is proposed to obtain a filtering response with four radiation nulls. The embedded resistor-loaded arms achieve two additional radiation nulls caused by reverse currents and absorb the unwanted out-of-band resonant points brought by themselves. The director close to the driver provides a resonant point and a radiation null caused by opposite currents between the driver and the director. Compared with other filtering quasi-Yagi antennas, the proposed one can achieve a filtering response with a compact size along the endfire direction. For demonstration, a balun-integrated prototype covering the 5G band N78 (3.3–3.8 GHz) is designed with the size along the endfire direction (without ground) of 0.13 λ0 (λ0 is the wavelength in the free space at center frequency), and the measured results show a 10 dB impedance-matching bandwidth of 22.9% (3.21–4.04 GHz), four radiation nulls, and a peak gain of 4.73 dBi.

Covalent organic frameworks (COFs) have emerged as promising electrocatalysts due to their controllable architectures, highly exposed molecular active sites, and ordered structures. In this study, a series of porphyrin-based COFs (TAPP-x-COF) with various transition metals (Co, Ni, Fe) were synthesized via a facile post-metallization strategy under solvothermal synthesis. The resulting porphyrin-based COFs showed oxygen reduction reaction (ORR) activity with a trend in Co > Fe > Ni. Among them, TAPP-Co-COF exhibited the best ORR activity (E1/2 = 0.66 V and jL = 4.82 mA cm−2) in alkaline media, which is comparable to those of Pt/C under the same conditions. Furthermore, TAPP-Co-COF was employed as a cathode in a Zn-air battery, demonstrating a high power density of 103.73 mW cm–2 and robust cycling stability. This work presents a simple method for using COFs as a smart platform to fabricate efficient electrocatalysts.

Development of porous proton-transporting materials combining stability and high performance has remained a challenge. Here, the authors report a stable covalent organic framework with excellent proton conductivity in which nitrogen sites on pore walls confine and stabilize a H3PO4 network in the channels via hydrogen-bonding interactions.

Covalent organic frameworks are crystalline porous polymers integrating molecular building blocks into periodic structures. Here, the authors report a general multiple-component condensation strategy that enables the use of one knot and two or three linkers to synthesize complex, anisotropic frameworks.