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Cobalt is considered an essential element for layered cathode active materials supporting enhanced lithium‐ion conductivity and structural stability. Herein, we investigated the influence of Co concentration on the physicochemical properties and electrochemical performance of lithium‐rich layered oxides (LRLOs) with different Co content (Li1.2Ni0.2‐x/2Mn0.6‐x/2CoxO2, x=0, 0.04, and 0.08). Though the presence of Co grants structural stability to LRLOs, superior long‐term cycling stability is achieved with the Co‐free LRLO retaining 88.1 % of the initial specific capacity (vs. 75.9 % of Li1.2Ni0.16Mn0.56Co0.08O2) after 300 galvanostatic cycles at 250 mA g−1 (1 C). The chemical stability on the surface of LRLOs containing Co declines faster, indicating a higher bulk structural stability not being the primary determinant of the LRLOs' cycling performance. Ex‐situ investigations indicate that the superior cycling stability of Co‐free LRLO is obtained by reducing the Mn‐related redox at discharge, which contributes to the large degree of polarization and low energy efficiency. Finally, the full‐cell configured with the optimized LRLO as cathode and graphite anode delivers an energy density of 464 Wh kg−1 at C/10, and 74.4 % and 94.3 % of retention in discharge specific capacity and average voltage at the 1000th cycle, demonstrating the applicability of Co‐free LRLO for sustainable LIBs. [ABSTRACT FROM AUTHOR]

Sodium batteries are an attractive alternative for future energy storage as they can be produced with abundant and low-cost materials. Nonetheless, sodium-ion batteries (SIBs) are often composed of flammable and volatile carbonate-based liquid electrolytes. Polymer electrolytes have attracted significant attention as safer alternatives. Among polymer electrolytes, single-ion conductive polymer electrolytes (SIPEs) are considered particularly interesting because they can suppress dendrite growth, enabling high-performance (quasi)-solid-state sodium–(metal) batteries. In this work, a self-standing, flexible, quasi-solid-state SIPE is investigated, which is composed of sodium 4-styrene sulfonyl (trifluoromethanesulfonyl) imide (NaSTFSI), pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) and pentaerythritol tetraacrylate (PET4A) blended with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). The SIPE membrane, including 50 wt% of molecular transporter, exhibits ionic conductivity of 1.4 × 10−5 S cm−1 and 1.3 × 10−4 S cm−1 at 20 °C and 90 °C, respectively, thermal stability up to 280 °C, electrochemical stability window up to 4.5 V vs. Na/Na+, and Na plating/stripping reversibility in symmetric Na‖Na cells. The manufactured SIPE implemented in Prussian White (PW)‖Na cells enables the delivery of 147 mA h g−1 of PW at 15 mA g−1 with a Coulombic efficiency of over 99%, which is comparable with the PW‖Na cells using liquid carbonate electrolyte, confirming the suitability of the designed SIPE for sodium–(metal) batteries. [ABSTRACT FROM AUTHOR]

In this study, the protic ionic liquid N,N-diethyl-3-sulfopropan-1-ammonium hydrogen methanedisulfonate is synthesized and characterized with the aim of elucidating its transport properties. A unique feature of this ionic liquid are the exchangeable acidic protons present on the anion and the cation, both of which contain low proton affinity sulfonic groups. The pronounced superionicity of this liquid, highlighted in the Walden-plot (ΔW > 0.8), indicates the decoupling of the conductivity from ionic diffusion. To explicate this enhanced proton mobility, the diffusion coefficients of the protons were measured by Pulsed-Field Gradient Spin-Echo NMR experiments at different temperatures. Below 373 K the diffusion coefficients of the cationic and anionic exchangeable protons are comparable with the ones of the other protons of the respective ions, indicating a vehicular transport mechanism. However, in the temperature range 383–413 K the diffusion coefficient of one of the exchangeable protons exceeds the diffusion of both ions by an unprecedented factor between 2 and 3. This temperature-induced switch in the proton transport mechanism is the result of a mixed-ion proton-transfer chain, as also supported by computational simulations. Both experimental and theoretical findings suggest the existence of a Grotthuss(-like) proton transport mechanism at high temperature in this system. [ABSTRACT FROM AUTHOR]

The EU's energy transition necessitates availability of green energy carriers with high volumetric energy densities for long‐term energy storage (ES) needs. A fully decarbonized scenario considering renewable energy availability is analyzed underpinning the need for such carriers. Considering the shortcomings of Power‐to‐X technologies in terms of efficiency and low volumetric density, Aluminum (Al) is identified as a potential alternative showing significantly high volumetric energy densities (23.5 kWh L−1). In this paper, an Al‐based long‐term ES concept is investigated, taking advantage of the inherent recycling of the active species (i.e., Al2O3 to Al) coupling decarbonized Hall–Héroult process with an Al‐steam oxidation for simultaneous hydrogen (H2) and heat generation. This work demonstrates an innovative lab‐scale fine Al powder‐steam oxidation process at ≈900 °C without use of catalysts or additives, exploiting alumina as inert material. Conducted SEM‐EDX analysis on oxidized Al provides supporting evidence in favor of employed oxidation pathway, hindering tendency of aluminum oxide (Al2O3) clumping and enabling direct use of oxides in the smelting process for fully recyclability. Moreover, outcomes of XRD analyses are presented to validate the measured total H2 yields. [ABSTRACT FROM AUTHOR]

Low‐temperature zinc batteries (LT‐ZIBs) based on aqueous electrolytes show great promise for practical applications owing to their natural resource abundance and low cost. However, they suffer from sluggish kinetics with elevated energy barriers due to the dissociation of bulky Zn(H2O)62+ solvation structure and free Zn2+ diffusion, resulting in unsatisfactory lifespan and performance. Herein, dissimilar to solvation shell tuning or layer spacing enlargement engineering, delocalized electrons in cathode through constructing intrinsic defect engineering is proposed to achieve a rapid electrocatalytic desolvation to obtain free Zn2+ for insertion/extraction. As revealed by density functional theory calculations and interfacial spectroscopic characterizations, the intrinsic delocalized electron distribution propels the Zn(H2O)62+ dissociation, forming a reversible interphase and facilitating Zn2+ diffusion across the electrolyte/cathode interface. The as‐fabricated oxygen defect‐rich V2O5 on hierarchical porous carbon (ODVO@HPC) electrode exhibits high capacity robustness from 25 to −20°C. Operating at −20°C, the ODVO@HPC delivers 191 mAh g−1 at 50 A g−1 and lasts for 50 000 cycles at 10 A g−1, significantly enhancing the power density and lifespan under low‐temperature environments in comparison to previous reports. Even with areal mass loading of ~13 mg cm−2, both coin cells and pouch batteries maintain excellent stability and areal capacities, realizing practical high‐performance LT‐ZIBs. [ABSTRACT FROM AUTHOR]

Cost‐effective and zero‐carbon‐emission seasonal/annual energy storage is highly required to achieve the Zero Emission Scenario (ZES) by 2050. The combination of Al production via inert‐anode smelting and Al conversion to electricity via Al−air batteries is a potential option. Although playing an important role in this approach, Al−air batteries, however, suffer from limited specific energy and inefficient collection of the discharge product. Herein, an important progress in addressing these issues is summarized, emphasizing the importance of non‐material, but rather process‐related aspects. First, a recently reported approach allowing controllable collection of discharge product and electrolyte regeneration is presented. Next, the importance of cell design in addressing the obstacles of Al−air batteries is emphasized. Subsequently, the impact of operational parameters on improving electrochemical performance of Al−air batteries is summarized. Last, a perspective on future research directions is proposed. [ABSTRACT FROM AUTHOR]