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In recent years, sodium‐ion batteries (SIBs) have attracted a lot of attention and are considered an ideal alternative to lithium‐ion batteries (LIBs). The hard carbon (HC) anode in SIBs presents a unique challenge for studying the formation process of the solid electrolyte interphase (SEI) during initial cycling, owing to its distinctive porous structure. This study employs a combination of ultrasonic scanning techniques and differential electrochemical mass spectrometry to conduct an in‐depth analysis of the two‐dimensional distribution and composition of gases during the formation process. The findings reveal distinct gas evolution behaviors in SIBs compared to LIBs during formation. Notably, significant gas evolution is observed during the discharge phase of the formation cycle in SIBs, with higher discharge rates leading to increased gas evolution rates. This phenomenon is likely attributed to the adsorption of CO2 gas by the abundant pores in HC, followed by desorption during discharge. Furthermore, the study demonstrates that the addition of 5A molecular sieves, which competitively adsorb gases, effectively reduces gas adsorption on the anode during formation, thereby significantly enhancing battery performance. This research elucidates the gas adsorption and desorption behavior at the battery interface, providing new insights into the SEI formation process in SIBs. [ABSTRACT FROM AUTHOR]

Metallene is considered as an emerging family of electrocatalysts due to its atomically layered structure and unique surface stress. Here we propose a strategy to modulate the Bader charge transfer (BCT) between Pd surface and oxygenated intermediates via p‐d electronic interaction by introducing single‐atom p‐block metal (M=In, Sn, Pb, Bi) into Pd metallene nanosheets towards efficient oxygen reduction reaction (ORR). X‐ray absorption and photoelectron spectroscopy suggests that doping p‐block metals could facilitate electron transfer to Pd sites and thus downshift the d‐band center of Pd and weaken the adsorption energy of O intermediates. Among them, the developed Bi−Pd metallene shows extraordinarily high ORR mass activity of 11.34 A mgPd−1 and 0.86 A mgPd−1 at 0.9 V and 0.95 V in alkaline solution, respectively, representing the best Pd‐based ORR electrocatalysts ever reported. In the cathode of a Zinc‐air battery, Bi−Pd metallene could achieve an open‐circuit voltage of 1.546 V and keep stable for 760 h at 10 mA cm−2. Theoretical calculations suggest that the BCT between Pd surface and *OO intermediates greatly affects the bond length between them (dPd‐*OO) and Bi doping could appropriately reduce the amount of BCT and stretch the dPd‐*OO, thus enhancing the ORR activity. [ABSTRACT FROM AUTHOR]

Developing efficient and anti‐corrosive oxygen reduction reaction (ORR) catalysts is of great importance for the applications of proton exchange membrane fuel cells (PEMFCs). Herein, we report a novel approach to prepare metal oxides supported intermetallic Pt alloy nanoparticles (NPs) via the reactive metal‐support interaction (RMSI) as ORR catalysts, using Ni‐doped cubic ZrO2 (Ni/ZrO2) supported L10−PtNi NPs as a proof of concept. Benefiting from the Ni migration during RMSI, the oxygen vacancy concentrations in the support are increased, leading to an electron enrichment of Pt. The optimal L10−PtNi−Ni/ZrO2−RMSI catalyst achieves remarkably low mass activity (MA) loss (17.8 %) after 400,000 accelerated durability test cycles in a half‐cell and exceptional PEMFC performance (MA=0.76 A mgPt−1 at 0.9 V, peak power density=1.52/0.92 W cm−2 in H2−O2/−air, and 18.4 % MA decay after 30,000 cycles), representing the best reported Pt‐based ORR catalysts without carbon supports. Density functional theory (DFT) calculations reveal that L10−PtNi−Ni/ZrO2−RMSI requires a lower energetic barrier for ORR than L10−PtNi−Ni/ZrO2 (direct loading), which is ascribed to a decreased Bader charge transfer between Pt and *OH, and the improved stability of L10−PtNi−Ni/ZrO2−RMSI compared to L10−PtNi−C can be contributed to the increased adhesion energy and Ni vacancy formation energy within the PtNi alloy. [ABSTRACT FROM AUTHOR]

The use of non‐solvating, or as‐called sparingly‐solvating, electrolytes (NSEs), is regarded as one of the most promising solutions to the obstacles to the practical applications of Li−S batteries. However, it remains a puzzle that long‐life Li−S batteries have rarely, if not never, been reported with NSEs, despite their good compatibility with Li anode. Here, we find the capacity decay of Li−S batteries in NSEs is mainly due to the accumulation of the dead Li2S at the cathode side, rather than the degradation of the anodes or electrolytes. Based on this understanding, we propose an electrochemical strategy to reactivate the accumulated Li2S and revive the dead Li−S batteries in NSEs. With such a facile approach, Li−S batteries with significantly improved cycling stability and accelerated dynamics are achieved with diglyme‐, acetonitrile‐ and 1,2‐dimethoxyethane‐based NSEs. Our finding may rebuild the confidence in exploiting non‐solvating Li−S batteries with practical competitiveness. [ABSTRACT FROM AUTHOR]

The well‐known "shuttle effect" of the intermediate lithium polysulfides (LiPSs) and low sulfur utilization hinder the practical application of lithium–sulfur (Li–S) batteries. Herein, we describe a novel C60–S supramolecular complex with high‐density active sites for LiPS adsorption that was formed by a simple one‐step process as a cathode material for Li–S batteries. Benefiting from the cocrystal structure, 100 % of the C60 molecules in the complex can offer active sites to adsorb LiPSs and catalyze their conversion. Furthermore, the lithiated C60 cores promote internal ion transport inside the composite cathode. At a low electrolyte/sulfur ratio of 5 μL mg−1, the C60–S cathode with a sulfur loading of 4 mg cm−2 exhibited a high capacity of 809 mAh g−1 (3.2 mAh cm−2). The development of the C60–S supramolecular complex will inspire the invention of a new family of S/fullerenes as cathodes for high‐performance Li–S batteries and extend the application of fullerenes. [ABSTRACT FROM AUTHOR]

LiCoO2 is used as a cathode material for lithium‐ion batteries, however, cationic/anodic‐redox‐induced unstable phase transitions, oxygen escape, and side reactions with electrolytes always occur when charging LiCoO2 to voltages higher than 4.35 V, resulting in severe capacity fade. Reported here is Mg‐pillared LiCoO2. Dopant Mg ions, serving as pillars in the Li‐slab of LiCoO2, prevent slab sliding in a delithiated state, thereby suppressing unfavorable phase transitions. Moreover, the resulting Li‐Mg mixing structure at the surface of Mg‐pillared LiCoO2 is beneficial for eliminating the cathode‐electrolyte interphase overgrowth and phase transformation in the close‐to‐surface region. Mg‐pillared LiCoO2 exhibits a high capacity of 204 mAh g−1 at 0.2 C and an enhanced capacity retention of 84 % at 1.0 C over 100 cycles within the voltage window of 3.0–4.6 V. In contrast, pristine LiCoO2 has a capacity retention of 14 % within the same voltage window. [ABSTRACT FROM AUTHOR]

Solid‐state Li metal batteries (SSLMBs) have attracted considerable interests due to their promising energy density as well as high safety. However, the realization of a well‐matched Li metal/solid‐state electrolyte (SSE) interface remains challenging. Herein, we report g‐C3N4 as a new interface enabler. We discover that introducing g‐C3N4 into Li metal can not only convert the Li metal/garnet‐type SSE interface from point contact to intimate contact but also greatly enhance the capability to suppress the dendritic Li formation because of the greatly enhanced viscosity, decreased surface tension of molten Li, and the in situ formation of Li3N at the interface. Thus, the resulting Li‐C3N4|SSE|Li‐C3N4 symmetric cell gives a significantly low interfacial resistance of 11 Ω cm2 and a high critical current density (CCD) of 1500 μA cm−2. In contrast, the same symmetric cell configuration with pristine Li metal electrodes has a much larger interfacial resistance (428 Ω cm2) and a much lower CCD (50 μA cm−2). [ABSTRACT FROM AUTHOR]

The commercialization of proton exchange membrane fuel cells (PEMFCs) relies on highly active and stable electrocatalysts for oxygen reduction reaction (ORR) in acid media. The most successful catalysts for this reaction are nanostructured Pt‐alloy with a Pt‐skin. The synthesis of ultrasmall and ordered L10‐PtCo nanoparticle ORR catalysts further doped with a few percent of metals (W, Ga, Zn) is reported. Compared to commercial Pt/C catalyst, the L10‐W‐PtCo/C catalyst shows significant improvement in both initial activity and high‐temperature stability. The L10‐W‐PtCo/C catalyst achieves high activity and stability in the PEMFC after 50 000 voltage cycles at 80 °C, which is superior to the DOE 2020 targets. EXAFS analysis and density functional theory calculations reveal that W doping not only stabilizes the ordered intermetallic structure, but also tunes the Pt‐Pt distances in such a way to optimize the binding energy between Pt and O intermediates on the surface. [ABSTRACT FROM AUTHOR]

The design of complex heterostructured electrode materials that deliver superior electrochemical performances to their individual counterparts has stimulated intensive research on configuring supercapacitors with high energy and power densities. Herein we fabricate hierarchical tectorum-like α-Fe2O3/polypyrrole (PPy) nanoarrays (T-Fe2O3/PPy NAs). The 3D, and interconnected T-Fe2O3/PPy NAs are successfully grown on conductive carbon cloth through an easy self-sacrificing template and in situ vapor-phase polymerization route under mild conditions. The electrode made of the T-Fe2O3/PPy NAs exhibits a high areal capacitance of 382.4 mF cm−2 at a current density of 0.5 mA cm−2 and excellent reversibility. The solid-state asymmetric supercapacitor consisting of T-Fe2O3/PPy NAs and MnO2 electrodes achieves a high energy density of 0.22 mWh cm−3 at a power density of 165.6 mW cm−3. [ABSTRACT FROM AUTHOR]