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Bipolar porous polymers bearing carbonyl and amine groups were designed and synthesized as cathode materials in Na-ion and K-ion batteries, demonstrating great promise for high-performance and sustainable batteries. 

Controlling network growth and architecture of 3D-conjugated porous polymers (CPPs) is challenging and therefore has limited the ability to systematically tune the network architecture and study its impact on doping efficiency and conductivity. We have proposed that π-face masking straps mask the π-face of the polymer backbone and therefore help to control π–π interchain interactions in higher dimensional π-conjugated materials unlike the conventional linear alkyl pendant solubilizing chains that are incapable of masking the π-face. Herein, we used cycloaraliphane-based π-face masking strapped monomers and show that the strapped repeat units, unlike the conventional monomers, help to overcome the strong interchain π–π interactions, extend network residence time, tune network growth, and increase chemical doping and conductivity in 3D-conjugated porous polymers. The straps doubled the network crosslinking density, which resulted in 18 times higher chemical doping efficiency compared to the control non-strapped-CPP. The straps also provided synthetic tunability and generated CPPs of varying network size, crosslinking density, dispersibility limit, and chemical doping efficiency by changing the knot to strut ratio. For the first time, we have shown that the processability issue of CPPs can be overcome by blending them with insulating commodity polymers. The blending of CPPs with poly(methylmethacrylate) (PMMA) has enabled them to be processed into thin films for conductivity measurements. The conductivity of strapped-CPPs is three orders of magnitude higher than that of the poly(phenyleneethynylene) porous network. 

Abstract Bipolar organic materials have emerged as promising cathode materials for rechargeable batteries because of their high voltage and high capacity. However, they suffer from poor cyclic stability and slow reaction kinetics. In this work, we designed and synthesized two bipolar organic cathode materials, containing carbonyl (n‐type) and amine (p‐type) functional groups, as well as extended conjugation structures, for Na‐ion batteries (NIBs) and rechargeable aluminum batteries (RABs). As universal electrode materials, bipolar organic materials exhibited exceptional electrochemical performance in terms of high capacity, high voltage, long cycle life, and fast rate capability. The extended conjugation structures in backbones of the bipolar organic materials facilitate the π–π stacking with graphene, playing a critical role in the high performance. Furthermore, the formation of a stable and robust NaF‐rich cathode electrolyte interphase was shown to stabilize the bipolar organic cathode in NIBs. Electrochemical kinetic measurements reveal that both functional groups undergo reversible redox reactions. Specifically, the electron transfer rate constant of the p‐type amine group is one order of magnitude higher than that of the n‐type carbonyl group. These results highlight the efficacy of developing bipolar organic materials for achieving high‐performance organic cathode in NIBs and RABs. 

Abstract In the human neocortex coherent interlaminar theta oscillations are driven by deep cortical layers, suggesting neurons in these layers exhibit distinct electrophysiological properties. To characterize this potential distinctiveness, we use in vitro whole-cell recordings from cortical layers 2 and 3 (L2&3), layer 3c (L3c) and layer 5 (L5) of the human cortex. Across all layers we observe notable heterogeneity, indicating human cortical pyramidal neurons are an electrophysiologically diverse population. L5 pyramidal cells are the most excitable of these neurons and exhibit the most prominent sag current (abolished by blockade of the hyperpolarization activated cation current, I h ). While subthreshold resonance is more common in L3c and L5, we rarely observe this resonance at frequencies greater than 2 Hz. However, the frequency dependent gain of L5 neurons reveals they are most adept at tracking both delta and theta frequency inputs, a unique feature that may indirectly be important for the generation of cortical theta oscillations. 

Abstract Redox‐active polymers (RAPs) are promising organic electrode materials for affordable and sustainable batteries due to their flexible chemical structures and negligible solubility in the electrolyte. Developing high‐dimensional RAPs with porous structures and crosslinkers can further improve their stability and redox capability by reducing the solubility and enhancing reaction kinetics. This work reports two three‐dimensional (3D) RAPs as stable organic cathodes in Na‐ion batteries (NIBs) and K‐ion batteries (KIBs). Carbonyl functional groups are incorporated into the repeating units of the RAPs by the polycondensation of Tetrakis(4‐aminophenyl)methane and two different dianhydrides. The RAPs with interconnected 3D extended conjugation structures undergo multi‐electron redox reactions and exhibit high performance in both NIBs and KIBs in terms of long cycle life (up to 8000 cycles) and fast charging capability (up to 2 A g⁻¹). The results demonstrate that developing 3D RAPs is an effective strategy to achieve high‐performance, affordable, and sustainable NIBs and KIBs. 

A disulfide made by oxidation of 8-thioguanosine is a supergelator. The hydrogels are redox-responsive, as they disassemble upon either reduction or oxidation of the S–S bond. We also identified this disulfide, and 2 other compounds, as intermediates in oxidative desulfurization of 8-thioG to guanosine.