Electron最新文献

With exceptional capacity during high-voltage cycling, P3-type Na-deficient layered oxide cathodes have captured substantial attention. Nevertheless, they are plagued by severe capacity degradation over cycling. In this study, tuning and optimizing the phase composition in layered oxides through Li incorporation are proposed to enhance the high-voltage stability. The structural dependence of layered Na_2/3Li_xNi_0.25Mn_0.75O_2+δ oxides on the lithium content (0.0 ≤ x ≤ 1.0) offered during synthesis is investigated systematically on an atomic scale. Surprisingly, increasing the Li content triggers the formation of mixed P2/O3-type or P3/P2/O3-type layered phases. As the voltage window is 1.5–4.5 V, P3-type Na_2/3Ni_0.25Mn_0.75O₂ (NL_0.0NMO, R$��\bar{3}�$m) material exhibits a sequence of phase transformations throughout the process of (de)sodiation, that is, O3⇌P3⇌O3′⇌O3″. Such complicated phase transitions can be effectively suppressed in the Na_2/3Li_0.7Ni_0.25Mn_0.75O_2.4 (NL_0.7NMO) oxide with P2/P3/O3-type mixed phases. Consequently, cathodes made of NL_0.7NMO exhibit a substantially enhanced cyclic performance at high voltages compared to that of the P3-type layered NL_0.0NMO cathode. Specifically, NL_0.7NMO demonstrates an outstanding capacity retention of 98% after 10 cycles at 1 C within 1.5–4.5 V, much higher than that of NL_0.0NMO (83%). This work delves into the intricate realm of bolstering the high-voltage durability of layered oxide cathodes, paving the way for advanced sodium-ion battery technologies.

Electrochemical water splitting for hydrogen generation is considered one of the most promising strategies for reducing the use of fossil fuels and storing renewable electricity in hydrogen fuel. However, the anodic oxygen evolution process remains a bottleneck due to the remarkably high overpotential of about 300 mV to achieve a current density of 10 mA cm⁻². The key to solving this dilemma is the development of highly efficient catalysts with minimized overpotential, long-term stability, and low cost. As a new 2D material, MXene has emerged as an intriguing material for future energy conversion technology due to its benefits, including superior conductivity, excellent hydrophilic properties, high surface area, versatile chemical composition, and ease of processing, which make it a potential constituent of the oxygen evolution catalyst layer. This review aims to summarize and discuss the recent development of oxygen evolution catalysts using MXene as a component, emphasizing the synthesis and synergistic effect of MXene-based composite catalysts. Based on the discussions summarized in this review, we also provide future research directions regarding electronic interaction, stability, and structural evolution of MXene-based oxygen evolution catalysts. We believe that a broader and deeper research in this area could accelerate the discovery of efficient catalysts for electrochemical oxygen evolution.

The industrial application of zinc-ion batteries is restricted by irrepressible dendrite growth and side reactions that resulted from the surface heterogeneity of the commercial zinc electrode and the thermodynamic spontaneous corrosion in a weakly acidic aqueous electrolyte. Herein, a common polar dye, Procion Red MX-5b, with high polarity and asymmetric charge distribution is introduced into the zinc sulfate electrolyte, which can not only reconstruct the solvation configuration of Zn²⁺ and strengthen hydrogen bonding to reduce the reactivity of free H₂O but also homogenize interfacial electric field by its preferentially absorption on the zinc surface. The symmetric cell can cycle with a lower voltage hysteresis (78.4 mV) for 1120 times at 5 mA cm⁻² and Zn//NaV₃O₈·1.5H₂O full cell can be cycled over 1000 times with high capacity (average 170 mAh g⁻¹) at 4 A g⁻¹ in the compound electrolyte. This study provides a new perspective for additive engineering strategies of aqueous zinc-ion batteries.

The Li metal anode emerges as a formidable competitor among anode materials for lithium–sulfur (Li-S) batteries; nevertheless, safety issues pose a significant hurdle in its path toward commercial viability. This review enumerates three historical challenges inherent to the Li metal anode: unavoidable volume expansion, multifunctional solid electrolyte interface formation, and uncontrollable lithium dendrite growth. In particular, when paired with a sulfur cathode, the Li anode presents an additional unique hurdle: the shuttle effect. To address these issues, this article offers a thorough examination of the latest innovations aimed at stabilizing the Li metal anode within Li-S batteries. We categorize these approaches into five classifications: liquid electrolyte optimization, enhancement of non-liquid-state electrolytes, Li metal surface modification, Li anode architecture design, and Li alloy improvement. For several noteworthy results within these categories, we have compiled their electrochemical performance into tables, facilitating direct comparison. This detailed analysis illuminates feasible strategies and suggests directions warranting further exploration for optimizing the capability and safety of Li metal anodes in Li-S batteries.

This picture mainly depicts the model of a Li-S battery circled by a Li metal ring, emphasizing the theme of Li metal anode in Li-S batteries. Some lithium dendrites are growing on the left of the ring while polysulfides composed of yellow balls(Sulfur ions) and metallic blue balls (lithium ions) are scattering on the right, precisely representing the lithium dendrites growing problem of Li metal anode and the shuttle effect as the unique problem in Li-S batteries. Meanwhile, the blue current on the ring implies the battery's operating status, echoing the journal's name,“Electron”.

The cover image is the structure diagram of bottom-gate staggered OTFT with the circuit diagram as the background, where the channel material is a typical small-molecule C₁₀-DNTT. The metal atoms can penetrate into the charge transport layer, with damage-free, via modulating organic crystal thickness during thermal evaporation of electrode. This could effectively reduce the contact resistance to aid the development of high-performance organic devices and circuits.

Orthorhombic Nb₂O₅ is a highly promising fast-charging anode material for sodium-ion capacitors. However, its poor intrinsic electronic/ionic conductivity limits its performance. Here, we developed a one-step heat treatment method to create an N-doped carbon coating on the outside and S-doped Nb₂O₅ on the inside (CN-SCN). Ionic liquids are used as the source of C/N/S, which synergistically enhance the surface and bulk electronic/ionic conductivity. The N-doped carbon coating on the surface exhibits excellent electronic conductivity and a low ion-diffusion barrier, thanks to the high nitrogen ratio and extremely low content (<2 wt%). Auger electron spectroscopy analysis confirms that S atoms detach from the carbon chain of the ionic liquids and enter the bulk Nb₂O₅, resulting in S-doped Nb₂O₅, significantly facilitating reaction kinetics. The CN-SCN electrodes exhibit outstanding rate capability, achieving a capacity of up to 94 mAh g⁻¹ even at a high current rate of 50 C. When paired with activated carbon as the positive electrode, the sodium-ion capacitor with the CN-SCN anode exhibits a high-energy density of up to 59 Wh kg⁻¹ and a long cycle life with 73% capacity retention after 10,000 cycles. This work opens up possibilities for low-cost and large-scale production of high-rate Nb₂O₅ for sodium-storage applications.

To reduce environmental pollution and plastic recycling costs, polyamide-66 (PA-66) as the most consumed engineering polymer needs to be recycled effectively. However, the existing recycling methods cannot convert waste PA-66 into valuable chemicals for upcycling under ambient conditions. Here, we report an integrated hydrolysis and electrocatalytic process to upcycle waste PA-66 into valuable adiponitrile (ADN), adipic acid, and H₂ commodities, thereby closing the PA-66 loop. To enable electrooxidation of the PA-66 hydrosylate hexamethylenediamine (HMD), we fabricated anode catalysts with hierarchical Ni₃S₂@Fe₂O₃ core-shell heterostructures comprising spindle-shaped Ni₃S₂ cores and Fe₂O₃ nanosheet shells. The unique core-shell architecture and synergy of the Ni₃S₂ and Fe₂O₃ catalysts enabled the selective dehydrogenation of C–N bonds from HMD to nitrile C≡N bonds, forming ADN with near-unity Faradaic efficiency at 1.40 V during the 100-h stability test even at 100 mA cm⁻². X-ray photoelectron spectroscopy revealed that the Ni(Fe) oxy(hydroxide) species formed were in the active state during oxidation, accelerating the activation of the amino C–N bond for dehydrogenation directly into the C≡N bonds.

Cathode electrolyte interphase (CEI) has a significant impact on the performance of rechargeable batteries and is gaining increasing attention. Understanding the fundamental and detailed CEI formation mechanism is of critical importance for battery chemistry. Herein, a diverse of characterization tools are utilized to comprehensively analyze the composition of the CEI layer as well as its formation mechanism by LiCoO₂ (LCO) cathode. We reveal that CEI is mainly composed of the reduction products of electrolyte and it only parasitizes the degraded LCO surface which has transformed into a disordered spinel structure due to oxygen loss and lithium depletion. Based on the energy diagram and the chemical potential analysis, the CEI formation process has been well explained, and the proposed CEI formation mechanism is further experimentally validated. This work highlights that the CEI formation process is nearly identical to that of the anode-electrolyte-interphase, both of which are generated due to the electrolyte directly in contact with the low chemical potential electrode material. This work can deepen and refresh our understanding of CEI.

The rising lithium metal batteries (LMBs) demonstrate a huge potential for improving the utilization duration of energy storage devices due to high theoretical energy density. Benefiting from the designs in the electrolyte, interface, and lithium host, several attempts have been made in the commercial application of LMBs. However, the application of lithium anode introduces additional safety risks and potential catastrophic accidents due to the high activity of lithium metal and dendrite during the electrochemical cycles. A comprehensive understanding of challenges and design issues on the safety hazards of LMBs in life cycle management is imperative for safe and commercial applications of LMBs. This paper first reviews emerging key safety issues and promising corresponding enhancements of LMBs during their production, utilization, and recycling. The wet air instability of lithium metal anode and gas production during activation have undoubtedly become the most intractable problems in LMBs production. It is necessary to use spraying technology to build a good protection layer upon lithium metal anode. Then, the growth of lithium dendrites poses a higher challenge to the utilization of LMBs, which requires the design of better electrolyte, anode skeleton, and other strategies as well as the prediction of LMBs life through big data and other methods. As for LMBs recovery, it is of great significance to choose the solvent to effectively control the consumption rate and temperature of highly reactive lithium metal powder. At last, further appeals and improvements are proposed for inspiring more related research to push forward the commercial use of LMBs.