Carbon Energy最新文献

The typical metal chloride-graphite intercalation compounds (MC-GICs) inherit intercalation capacity, high charge conductivity, and high tap density from graphite, and these are considered as one of the promising alternatives of graphite anode in rechargeable metal-ion batteries (MIBs). Notably, the special interlayer decoupling effects and the introduction of extra conversion capacity by metal chloride could greatly break the capacity limitation of graphite anodes and achieve higher energy density in MIBs. The optimization of both graphite host and metal chloride species with specific structures endows MC-GICs with design feasibility for different application requirements of different MIBs, such as several times the actual capacity compared to graphite anodes, rapid migration of large carriers, and other properties. Herein, a brief review has been provided with the latest understanding of conductivity characteristics and energy storage mechanisms of MC-GICs and their interesting performance features of full potential application in rechargeable MIBs. Based on the existing research of MC-GICs, necessary improvements and prospects in the near future have been put forward.

Efficient electrocatalysis at the cathode is crucial to addressing the limited stability and low rate capability of Li−O₂ batteries. This study examines the kinetic behavior of Li−O₂ batteries utilizing layered perovskite LaSrCrO₄ nanowires (NWs) composed of lower oxidation states. Layered perovskite LaSrCrO₄ NWs exhibited improved rate capability over a wide range of current densities and longer cycle life in Li−O₂ batteries than V-based layered perovskite (LaSrVO₄) and simple perovskite (La_0.8Sr_0.2CrO₃) NWs. X-ray photoelectron spectroscopy and electrochemical surface area analyses showed that the observed performance variations primarily stemmed from active sites such as oxygen vacancies. In situ Raman analysis showed that these active sites significantly modulate the kinetics of oxygen reduction and evolution, which are related to LiO₂ intermediate adsorption. Electrochemical impedance spectroscopy showed that the active sites in layered perovskite LaSrCrO₄ NWs contributed to their high charge transfer capability and reduced polarization. This study presents an appealing method for the precise fabrication and analysis of Cr-based layered perovskites, aimed at achieving highly efficient and stable bifunctional oxygen electrocatalysis.

Back cover image: The ion transport properties of porous membrane materials are essential in numerous applications, and achieving synergistic enhancement of both permeability and selectivity remains a significant challenge. In the article number cey2.458, Zhu and co-workers reported a strategy to address this challenge by developing a charge-tunable nanofluidic membrane. Inserting chargetunable copolymers into GO membranes, effectively matches the charge density of the membrane with the pore size. This synergistic enhancement strategy led to a nearly 10-fold increase in osmotic energy generation, and it was expected to optimize the energy structure and promote the utilization and conversion of clean energy in the future.

Front cover image: Electrocatalytic CO₂ reduction to syngas (CO and H₂) offers an efficient way to mitigate carbon emissions and store intermittent renewable energy in chemicals. However, it is tricky to produce an adjustable ratio of syngas due to the difficulty of maintaining a balance between CO₂ reduction reaction (CO₂RR) and the competing hydrogen evolution reaction (HER). In article number cey2.461, Zhang et al. prepare hierarchical one-dimensional/three-dimensional nitrogen-doped porous carbon (1D/3D NPC) by carbonizing the composite of Zn-MOF-74 crystals in situ grown on a commercial melamine sponge (MS). Benefiting from the unique spatial environment of 1D/3D NPC, the reaction kinetics is significantly improved by increasing specific surface areas, CO₂ adsorption, mass transport, and facilitating electron transfer from the 3D N-doped carbon framework to 1D porous carbon. The bifunctional activity of N-doped carbon materials for CO₂RR and HER is beneficial for regulating the balance between CO₂RR and HER. The carbonizing temperatures can affect the distribution of N species and further dominate syngas composition ratios.

The commercial utilization of Zn metal anodes with high plating capacity is significantly hindered by the uncontrolled growth of dendrites and associated side reactions. Herein, a robust artificial ion-sieving MXene flake (MXF)-coating layer, with abundant polar terminated groups, is constructed to regulate the interfacial Zn²⁺ deposition behavior. In particular, the fragmented MXF coupled with in situ generated quantum dots not only has strong Zn affinity to homogenize electric fields but also generates numerous zincophilic sites to reduce nucleation energy, thus securing a uniform dendrite-free surface. Additionally, the porous coating layer with polar groups allows the downward diffusion of Zn²⁺ to achieve bottom-up deposition and repels the excessive free water and anions to prevent parasitic reactions. The ion-sieving effect of MXF is firmly verified in symmetric cells with high areal capacity of 10–40 mAh cm⁻² (1.0 mA cm⁻²) and depth of discharge of 15%–60%. Therefore, the functional MXF-coated anode manifests long-term cycling with 2700 h of stable plating/stripping in Zn||Zn cell. Such rational design of MXF protective layer breaks new ground in developing high plating capacity zinc anodes for practical applications.