Stretchable ionic conductors are considerable to be the most attractive candidate for next-generation flexible ionotronic devices. Nevertheless, high ionic conductivity, excellent mechanical properties, good self-healing capacity and recyclability are necessary but can be rarely satisfied in one material. Herein, we propose an ionic conductor design, dynamic supramolecular ionic conductive elastomers (DSICE), via phase-locked strategy, wherein locking soft phase polyether backbone conducts lithium-ion (Li+) transport and the combination of dynamic disulfide metathesis and stronger supramolecular quadruple hydrogen bonds in the hard domains contributes to the self-healing capacity and mechanical versatility. The dual-phase design performs its own functions and the conflict among ionic conductivity, self-healing capability, and mechanical compatibility can be thus defeated. The well-designed DSICE exhibits high ionic conductivity (3.77 × 10−3 S m−1 at 30 °C), high transparency (92.3%), superior stretchability (2615.17% elongation), strength (27.83 MPa) and toughness (164.36 MJ m−3), excellent self-healing capability (~99% at room temperature) and favorable recyclability. This work provides an interesting strategy for designing the advanced ionic conductors and offers promise for flexible ionotronic devices or solid-state batteries.

Fundamental understanding of constructing elevated catalysts to realize fast electron transfer and rapid mass transport in oxygen reduction reaction (ORR) chemistry by interface regulation and structure design is important but still ambiguous. Herein, a novel jellyfish-like Mott-Schottkytype electrocatalyst is developed to realize fast electron transfer and decipher the structure-mass transport connection during ORR process. Both spectroscopy techniques and density functional theory calculation demonstrate electrons spontaneously transfer from Fe to N-doped graphited carbon at the heterojunction interface, thus accelerating electron transfer from electrode to reactant. Dynamic analysis indicates unique structure can significantly improve mass transport of oxygen-species due to two factors: one is electrolyte streaming effect caused by tentacle-like carbon nanotubes; the other is effective collision probability in the semiclosed cavity. Therefore, this Mott-Schottky-type catalyst delievers superior ORR performance with high onset potential, positive half wave potential, and large current density. It also exhibits low overpotential when serving as an air cathode in Zn-air batteries. This work deepens understanding of the two key factors-electron transfer and mass transport-on determining the kinetic reaction of ORR process and offers a new avenue in constructing efficient Mott-Schottky electrocatalysts.

Rechargeable Li−CO 2 batteries have been receiving intense interest because of their high theoretical energy density and environmentally friendly CO 2 fixation ability. However, due to the sluggish CO 2 reduction/ evolution reaction (CRR/CER) kinetics, the current Li−CO 2 batteries still suffer from severe polarization and poor cycling stability. Herein, we designed and in situ synthesized sea urchinlike Mn 2 O 3 −Mn 3 O 4 nanocomposite and explored the synergistic effect between Mn 2 O 3 and Mn 3 O 4 during charge− discharge process in Li−CO 2 batteries. It is found that Mn 3 O 4 can effectively promote the kinetics of CRR process, and Mn 2 O 3 can induce the nucleation of Li 2 CO 3 and promote its decomposition (CER). Benefiting from the dual-phase synergy, the Mn 2 O 3 −Mn 3 O 4 cathode combines the respective catalytic advantages of the both and delivers a high full discharge capacity of 19 024 mAh g −1 , a low potential gap of 1.24 V, and durable cycling stability (1380 h) at a current density of 100 mA g −1 . Moreover, based on experimental results and density functional theory (DFT) calculations, a charge−discharge process model of the Mn 2 O 3 −Mn 3 O 4 cathode was established to display the electrochemical reaction mechanism. We hope that this design strategy can encourage further studies for efficient cathode catalysts to accelerate the practical application of Li−CO 2 batteries and even the metal−air batteries.

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battery has recently attracted worldwide attention due to its ultrahigh theoretical energy density of 1876 W h kg −1 , far exceeding that of state-of-art Li-ion batteries (≈387 W h kg −1 ). [2] The electrochemical reaction of a typical aprotic Li-CO 2 battery is 4Li + + 3CO 2 + 4e − ↔ 2Li 2 CO 3 + C (E Φ = 2.80 V vs Li/Li + ). [3] The equation shows the use of CO 2 as a renewable energy carrier in Li-CO 2 batteries, providing a novel approach for eco-efficient CO 2 fixation and utilization. [4] However, the technical application of the current Li-CO 2 battery is critically hindered by low energy efficiency, limited areal capacity, and poor cycle life.The critical challenges are associated with 1) the activation of thermodynamically stable CO 2 molecules, 2) sluggish reaction kinetics of Li 2 CO 3 decomposition due to its wide bandgap, and 3) the slow mass transfer on the multiphase interface. The first of these problems leads to low discharge potential and rapid capacity degradation; the second causes high charge potential; and the last limits high rate and long cycle performance. In response, a variety of cathode catalysts have been explored to improve the electrochemical performance of the Li-CO 2 battery. [5] To date, noble metal Ru-based catalysts have been frequently used as cathode catalysts due to their unique electronic configuration and high chemical stability. For example, Ru@super P was first reported as an excellent catalyst to promote the reversible decomposition of Li 2 CO 3 and C. [6] Afterward, Ru-Cu Graphene, [7] RuRh nanosheets, [8] Ru@CNT, [9] Ru/NiO@ Ni/CNT, [5c] and Ru/Ni foam [10] were used as cathode catalysts, which can improve the electrochemical performance of Li-CO 2 battery to a certain extent. However, the reported work generally demonstrated limited areal capacity due to the low active material loading, severely constraining the battery's potential in practical applications. In addition, an in-depth understanding of the catalytic mechanism is still lacking. Therefore, it is crucial to explore the process of CO 2 reduction and evolution reaction (CRR and CER) during discharge-charge processes and propose a reasonable design strategy of high-area-capacity cathode catalysts for the development of Li-CO 2 batteries.The sluggish kinetics of CO 2 reduction and evolution reaction (CRR and CER) on the Li-CO 2 battery cathode seriously hindered its practical application. Rational design of the Ru/C interface is expected to simultaneously decrease the free energy barrier of intermediate species and create a favorable electronic structure, effectively promoting the catalytic reaction kinetics of the CRR and CER. Herein, a 3D self-supporting cellulose carbon aerogel (CCA) with well-defined Ru/C interfaces (Ru@CCA) is synthesized as an advanced CO 2 -breathing cathode for Li-CO 2 batteries. The results show that the energy efficiency significantly improves to 80% with a high discharge capacity of 10.71 mA h cm −2 at 20 µA cm −2 , and excellent cyclic stability of 421 cycles at 100 µA cm −2 . ...