能源化学最新文献

With the rapid development of rechargeable metal-ion batteries (MIBs) with safety, stability and high energy density, significant efforts have been devoted to exploring high-performance electrode materials. In recent years, two-dimensional (2D) molybdenum-based (Mo-based) materials have drawn considerable attention due to their exceptional characteristics, including low cost, unique crystal structure, high theoretical capacity and controllable chemical compositions. However, like other transition metal compounds, Mo-based materials are facing thorny challenges to overcome, such as slow electron/ion transfer kinetics and substantial volume changes during the charge and discharge processes. In this review, we summarize the recent progress in developing emerging 2D Mo-based electrode materials for MIBs, encompassing oxides, sulfides, selenides, carbides. After introducing the crystal structure and common synthesis methods, this review sheds light on the charge storage mechanism of several 2D Mo-based materials by various advanced characterization techniques. The latest achievements in utilizing 2D Mo-based materials as electrode materials for various MIBs (including lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) and zinc-ion batteries (ZIBs)) are discussed in detail. Afterwards, the modulation strategies for enhancing the electrochemical performance of 2D Mo-based materials are highlighted, focusing on heteroatom doping, vacancies creation, composite coupling engineering and nanostructure design. Finally, we present the existing challenges and future research directions for 2D Mo-based materials to realize high-performance energy storage systems.

Electrocatalytic overall water splitting (OWS), a pivotal approach in addressing the global energy crisis, aims to produce hydrogen and oxygen. However, most of the catalysts in powder form are adhesively bounding to the electrodes, resulting in catalyst detachment by bubble generation and other uncertain interference, and eventually reducing the OWS performance. To surmount this challenge, we synthesized a hybrid material of Co₃S₄- pyrolysis lotus fiber (labeled as Co₃S₄-pLF) textile by hydrothermal and high-temperature pyrolysis processes for electrocatalytic OWS. Owing to the natural LF textile exposing the uniformly distributed functional groups (OH, NH₂, etc.) to anchor Co₃S₄ nanoparticles with hierarchical porous structure and outstanding hydrophily, the hybrid Co₃S₄-pLF catalyst shows low overpotentials at 10 mA cm⁻² (η_{10, HER} = 100 mV η_{10, OER} = 240 mV) alongside prolonged operational stability during electrocatalytic reactions. Theoretical calculations reveal that the electron transfer from pLF to Co₃S₄ in the hybrid Co₃S₄-pLF is beneficial to the electrocatalytic process. This work will shed light on the development of nature-inspired carbon-based materials in hybrid electrocatalysts for OWS.

The safety valve is an important component to ensure the safe operation of lithium-ion batteries (LIBs). However, the effect of safety valve type on the thermal runaway (TR) and gas venting behavior of LIBs, as well as the TR hazard severity of LIBs, are not known. In this paper, the TR and gas venting behavior of three 100 A h lithium iron phosphate (LFP) batteries with different safety valves are investigated under overheating. Compared to previous studies, the main contribution of this work is in studying and evaluating the effect of gas venting behavior and TR hazard severity of LFP batteries with three safety valve types. Two significant results are obtained: (I) the safety valve type dominates over gas venting pressure of battery during safety venting, the maximum gas venting pressure of LFP batteries with a round safety valve is 3320 Pa, which is one order of magnitude higher than other batteries with oval or cavity safety valve; (II) the LFP battery with oval safety valve has the lowest TR hazard as shown by the TR hazard assessment model based on gray-fuzzy analytic hierarchy process. This study reveals the effect of safety valve type on TR and gas venting, providing a clear direction for the safety valve design.

Smart wearable devices are regarded to be the next prevailing technology product after smartphones and smart homes, and thus there has recently been rapid development in flexible electronic energy storage devices. Among them, flexible solid-state zinc-air batteries have received widespread attention because of their high energy density, good safety, and stability. Efficient bifunctional oxygen electrocatalysts are the primary consideration in the development of flexible solid-state zinc-air batteries, and self-supported air cathodes are strong candidates because of their advantages including simplified fabrication process, reduced interfacial resistance, accelerated electron transfer, and good flexibility. This review outlines the research progress in the design and construction of nanoarray bifunctional oxygen electrocatalysts. Starting from the configuration and basic principles of zinc-air batteries and the strategies for the design of bifunctional oxygen electrocatalysts, a detailed discussion of self-supported air cathodes on carbon and metal substrates and their uses in flexible zinc-air batteries will follow. Finally, the challenges and opportunities in the development of flexible zinc-air batteries will be discussed.

Blade batteries are extensively used in electric vehicles, but unavoidable thermal runaway is an inherent threat to their safe use. This study experimentally investigated the mechanism underlying thermal runaway propagation within a blade battery by using a nail to trigger thermal runaway and thermocouples to track its propagation inside a cell. The results showed that the internal thermal runaway could propagate for up to 272 s, which is comparable to that of a traditional battery module. The velocity of the thermal runaway propagation fluctuated between 1 and 8 mm s⁻¹, depending on both the electrolyte content and high-temperature gas diffusion. In the early stages of thermal runaway, the electrolyte participated in the reaction, which intensified the thermal runaway and accelerated its propagation. As the battery temperature increased, the electrolyte evaporated, which attenuated the acceleration effect. Gas diffusion affected thermal runaway propagation through both heat transfer and mass transfer. The experimental results indicated that gas diffusion accelerated the velocity of thermal runaway propagation by 36.84%. We used a 1D mathematical model and confirmed that convective heat transfer induced by gas diffusion increased the velocity of thermal runaway propagation by 5.46%–17.06%. Finally, the temperature rate curve was analyzed, and a three-stage mechanism for internal thermal runaway propagation was proposed. In Stage I, convective heat transfer from electrolyte evaporation locally increased the temperature to 100 °C. In Stage II, solid heat transfer locally increases the temperature to trigger thermal runaway. In Stage III, thermal runaway sharply increases the local temperature. The proposed mechanism sheds light on the internal thermal runaway propagation of blade batteries and offers valuable insights into safety considerations for future design.

Safe batteries are the basis for next-generation application scenarios such as portable energy storage devices and electric vehicles, which are crucial to achieving carbon neutralization. Electrolytes, separators, and electrodes as main components of lithium batteries strongly affect the occurrence of safety accidents. Responsive materials, which can respond to external stimuli or environmental change, have triggered extensive attentions recently, holding great promise in facilitating safe and smart batteries. This review thoroughly discusses recent advances regarding the construction of high-safety lithium batteries based on internal thermal-responsive strategies, together with the corresponding changes in electrochemical performance under external stimulus. Furthermore, the existing challenges and outlook for the design of safe batteries are presented, creating valuable insights and proposing directions for the practical implementation of safe lithium batteries.

The recycling and reutilization of spent lithium-ion batteries (LIBs) have become an important measure to alleviate problems like resource scarcity and environmental pollution. Although some progress has been made, battery recycling technology still faces challenges in terms of efficiency, effectiveness and environmental sustainability. This review aims to systematically review and analyze the current status of spent LIB recycling, and conduct a detailed comparison and evaluation of different recycling processes. In addition, this review introduces emerging recycling techniques, including deep eutectic solvents, molten salt roasting, and direct regeneration, with the intent of enhancing recycling efficiency and diminishing environmental repercussions. Furthermore, to increase the added value of recycled materials, this review proposes the concept of upgrading recycled materials into high value-added functional materials, such as catalysts, adsorbents, and graphene. Through life cycle assessment, the paper also explores the economic and environmental impacts of current battery recycling and highlights the importance that future recycling technologies should achieve a balance between recycling efficiency, economics and environmental benefits. Finally, this review outlines the opportunities and challenges of recycling key materials for next-generation batteries, and proposes relevant policy recommendations to promote the green and sustainable development of batteries, circular economy, and ecological civilization.

The balance between cationic redox and oxygen redox in layer-structured cathode materials is an important issue for sodium batteries to obtain high energy density and considerable cycle stability. Oxygen redox can contribute extra capacity to increase energy density, but results in lattice instability and capacity fading caused by lattice oxygen gliding and oxygen release. In this work, reversible Mn²⁺/Mn⁴⁺ redox is realized in a P3-Na_0.65Li_0.2Co_0.05Mn_0.75O₂ cathode material with high specific capacity and structure stability via Co substitution. The contribution of oxygen redox is suppressed significantly by reversible Mn²⁺/Mn⁴⁺ redox without sacrificing capacity, thus reducing lattice oxygen release and improving the structure stability. Synchrotron X-ray techniques reveal that P3 phase is well maintained in a wide voltage window of 1.5–4.5 V vs. Na⁺/Na even at 10 C and after long-term cycling. It is disclosed that charge compensation from Co/Mn-ions contributes to the voltage region below 4.2 V and O-ions contribute to the whole voltage range. The synergistic contributions of Mn²⁺/Mn⁴⁺, Co²⁺/Co³⁺, and O²⁻/(O_n)²⁻ redox in P3-Na_0.65Li_0.2Co_0.05Mn_0.75O₂ lead to a high reversible capacity of 215.0 mA h g⁻¹ at 0.1 C with considerable cycle stability. The strategy opens up new opportunities for the design of high capacity cathode materials for rechargeable batteries.

Vanadium-based electrodes are regarded as attractive cathode materials in aqueous zinc ion batteries (ZIBs) caused by their high capacity and unique layered structure. However, it is extremely challenging to acquire high electrochemical performance owing to the limited electronic conductivity, sluggish ion kinetics, and severe volume expansion during the insertion/extraction process of Zn²⁺. Herein, a series of V₂O₃ nanospheres embedded N-doped carbon nanofiber structures with various V₂O₃ spherical morphologies (solid, core–shell, hollow) have been designed for the first time by an electrospinning technique followed thermal treatments. The N-doped carbon nanofibers not only improve the electrical conductivity and the structural stability, but also provides encapsulating shells to prevent the vanadium dissolution and aggregation of V₂O₃ particles. Furthermore, the varied morphological structures of V₂O₃ with abundant oxygen vacancies can alleviate the volume change and increase the Zn²⁺ pathway. Besides, the phase transition between V₂O₃ and Zn_XV₂O_5−m·nH₂O in the cycling was also certified. As a result, the as-obtained composite delivers excellent long-term cycle stability and enhanced rate performance for coin cells, which is also confirmed through density functional theory (DFT) calculations. Even assembled into flexible ZIBs, the sample still exhibits superior electrochemical performance, which may afford new design concept for flexible cathode materials of ZIBs.