Juan Fang

Lithium metal batteries are regarded as a key candidate for next-generation high-energy-density energy storage batteries owing to their ultrahigh theoretical specific capacity. Nevertheless, the evolution law of isolated lithium and continuous generation of dead lithium during cycling remain unclear, which severely restrict the cycling lifespan and fast-charging performance of batteries. To address this challenge, a phase-field model capable of accurately characterizing the spontaneous formation of isolated lithium is established based on phase equilibrium phase transition theory combined with dynamic electrochemical processes of lithium deposition and stripping. The intrinsic physical mechanism of solid-liquid phase transition in electrolytes under electric field modulation is revealed. Based on the proposed model, the regulation effects of pulse parameters on the growth morphologies of dendritic and mossy lithium are systematically investigated. The results verify that single nucleation optimization and skeleton structure modification fail to fundamentally restrain isolated lithium generation during stripping. Accordingly, a dual-stage differential electric field structure of the anode skeleton is rationally designed via numerical simulation, and an asymmetric electric-field modulation strategy compatible with lithium plating and stripping processes is established. This design successfully achieves bottom-up uniform lithium deposition and enables stable and controllable top-down lithium stripping. Combined with in-situ optical microscopic observations, the reliability of simulation results is validated, and the electric field response evolution characteristics of isolated lithium are further clarified. Integrating theoretical simulation and experimental verification, this study systematically reveals the formation and evolution mechanisms of isolated lithium. It provides a significant theoretical basis for suppressing isolated lithium accumulation, improving the cycling stability of lithium metal anodes, and advancing the technological upgrading of high-energy-density fast-charging energy storage batteries.

Lithium metal batteries are regarded as a key candidate for next-generation high-energy-density energy storage batteries owing to their ultrahigh theoretical specific capacity. Nevertheless, the evolution law of isolated lithium and continuous generation of dead lithium during cycling remain unclear, which severely restrict the cycling lifespan and fast-charging performance of batteries. To address this challenge, a phase-field model capable of accurately characterizing the spontaneous formation of isolated lithium is established based on phase equilibrium phase transition theory combined with dynamic electrochemical processes of lithium deposition and stripping. The intrinsic physical mechanism of solid-liquid phase transition in electrolytes under electric field modulation is revealed. Based on the proposed model, the regulation effects of pulse parameters on the growth morphologies of dendritic and mossy lithium are systematically investigated. The results verify that single nucleation optimization and skeleton structure modification fail to fundamentally restrain dead lithium generation during stripping. Accordingly, a dual-stage differential electric field configuration of anode skeleton is designed, and an asymmetric electric field regulation strategy matching plating and stripping processes is constructed. Uniform bottom-up lithium deposition and stable top-down controllable lithium stripping are achieved successfully. Combined with in-situ optical microscopic observations, the reliability of simulation results is validated, and the spatial migration and electric field response evolution characteristics of isolated lithium are further clarified. Integrating theoretical simulation and experimental verification, this study systematically reveals the formation and evolution mechanisms of isolated lithium and dead lithium. It provides a significant theoretical basis for suppressing dead lithium accumulation, improving the cycling stability of lithium metal anodes, and advancing the technological upgrading of high-energy-density fast-charging energy storage batteries.

As China’s carbon inclusion policies are gradually implemented, significant progress has been made in energy conservation and emission reduction. The economical use of energy is the basis for the reduction in carbon emissions, which is a direct reflection of the benefits of energy efficiency initiatives. Nonetheless, the lack of technological innovation, challenges in carbon emission monitoring, low levels of public participation, and inadequate talent cultivation present significant obstacles to the development of energy conservation and carbon inclusion. This paper, grounded in the theory of planned behavior (TPB), addresses the issue of low public participation in emission reduction initiatives. By employing a questionnaire survey, designing a 5-point Likert scale, and utilizing SPSS techniques for regression analysis and chi-square testing, this study explores and analyzes the potential factors influencing public willingness to engage in carbon emission reduction initiatives (CERIs). This research provides theoretical reference for relevant government agencies and industry insiders to formulate and implement the policies of energy saving and carbon reduction and provides targeted suggestions for China’s energy market to help them realize the sustainable development of low-carbon, energy saving, and environmental protection.

Lithium-ion batteries are the backbone of novel energy vehicles and ultimately contribute to a more sustainable and environmentally friendly transportation system. Taking a 5 Ah ternary lithium-ion battery as an example, a two-dimensional axisymmetric electrochemical–thermal coupling model is developed via COMSOL Multiphysics 6.0 in this study and then is validated with the experimental data. The proportion of different types of heat generation in a 26,650 ternary lithium-ion battery during the charge/discharge cycle is investigated numerically. Moreover, the impact of essential factors such as charge/discharge multiplier and ambient temperature on the reaction heat, ohmic heat, and polarization heat are analyzed separately. The numerical results indicate that the total heat generated by the constant discharge process is the highest in the charging and discharging cycle of a single battery. The maximum heat production per unit volume is 67,446.99 W/m³ at 2 C multiplier discharge. Furthermore, the polarization heat presents the highest percentage in the charge/discharge cycle, reaching up to 58.18% at 0 C and 1 C multiplier discharge. In a high-rate discharge, the proportion of the reaction heat decreases from 34.31% to 12.39% as the discharge rate increases from 0.5 C to 2 C. As the discharge rate rises and the ambient temperature falls, the maximum temperature increase of the single-cell battery also rises, with a more pronounced impact compared to increasing the discharge rate.

Micro compressed air energy storage systems are a research hotspot in the field of compressed air energy storage technology. Compressors and expanders are the core equipment for energy conversion, and their performance has a significant impact on the performance of the entire compressed air energy storage system. Scroll compressors have the advantages of small size, low noise, light weight, low vibration, long service life, continuous and stable gas transmission, and reliable operation. This article builds a micro compressed air energy storage system based on a scroll compressor and studies the effects of key parameters such as speed, torque, current, and storage tank pressure on the temperature difference, pressure ratio, energy consumption, and efficiency of the scroll compressor. The experimental results indicate that the power consumption of the scroll compressor shows an increasing trend with the increase in current, torque, and gas storage tank pressure. The isentropic efficiency of a scroll compressor shows a decreasing trend with increasing current, torque, and storage tank pressure. The maximum values of power consumption and isentropic efficiency of the scroll compressor are 3427 W and 90.8%, respectively.

Finding new supports and reducing the amount of platinum are key steps in the development of fuel cells. Herein, nanoscale WC is used as the support for a Pt catalyst, which was prepared by an improved strategy based on solution combustion and chemical reduction. After high-temperature carbonization, the synthesized Pt/WC catalyst displayed a well-distributed size distribution and relatively fine particles, which consisted of WC and modified Pt nanoparticles. Meanwhile, the excess carbon of the precursor transformed into amorphous carbon in the high-temperature process. The formation carbon layer on the surface of the WC nanoparticles had a significant effect on the microstructure of the Pt/WC catalyst, improving the conductivity and stability of Pt. Linear sweep voltammetry and Tafel plots were used to evaluate the catalytic activity and mechanism for the hydrogen evolution reaction. As compared with the WC and commercial Pt/C catalysts, the Pt/WC catalyst showed the highest activity with η10 of 32.3 mV and a Tafel slope of 30 mV·dec⁻¹ towards HER in acidic solution. These studies confirm that the formation of surface carbon can increase material stability and conductivity, improving the synergistic relationships between Pt and WC catalysts, leading to an increase of catalytic activity.