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The liquid-phase mass transport is the key factor affecting battery stability. The influencing mechanism of liquid-phase mass transport in the separators is still not clear, the internal environment being a complex multi-field during the service life of lithium-ion batteries. The liquid-phase mass transport in the separators is related to the microstructure of the separator and the physicochemical properties of electrolytes. Here, in-situ local electrochemical impedance spectra were developed to investigate local inhomogeneities in the mass transfer process of lithium-ion batteries. The geometric microstructure of the separator significantly impacts the mass transfer process, with a reduction in porosity leading to increased overpotentials. A competitive relationship among porosity, tortuosity, and membrane thickness in the geometric parameters of the separator were established, resulting in a peak of polarization. The resistance of the liquid-phase mass transfer process is positively correlated with the viscosity of the electrolyte, hindering ion migration due to high viscosity. Polarization is closely related to the electrochemical performance, so a phase diagram of battery performance and inhomogeneous mass transfer was developed to guide the design of the battery. This study provides a foundation for the development of high stability lithium-ion batteries., (© 2024 Wiley-VCH GmbH.)

Photovoltaic cells (PVs) are able to convert solar energy to electric energy, while energy storage devices are required to be equipped due to the fluctuations of sunlight. However, the electrical connection of PVs and energy storage devices leads to increased energy consumption, and thus energy storage ability and utilization efficiency are decreased. One of the solutions is to explore an integrated photoelectrochemical energy conversion-storage device. Up to date, the integrated photo-rechargeable Li-ion batteries often suffer from unstable photo-active materials and flammable electrolytes under illumination, with concerns in safety risks and limited lifetime. To address the critical issues, here a novel photo-rechargeable aluminum battery (PRAB) is designed with safe ionic liquid electrolytes and stable polyaniline photo-electrodes. The integrated PRAB presents stable operation with an enhanced reversible specific capacity ≈191% under illumination. Meanwhile, a simplified continuum model is established to provide rational guidance for designing electrode structures along with a charging/discharging strategy to meet the practical operation conditions. The as-designed PRAB presents an energy-saving efficiency ≈61.92% upon charging and an energy output increment ≈31.25% during discharging under illumination. The strategy of designing and fabricating stable and safe photo-rechargeable non-aqueous Al batteries highlights the pathway for substantially promoting the utilization efficiency of solar energy., (© 2024 Wiley‐VCH GmbH.)

The relationship between interface structure (e. g., the facet of the solid phase and the configuration of solvation) and the reactivity of the corresponding electrode is a critical issue in electrochemistry. Compared to macroscopic electrode measurements, electrochemical methods established on the single-particle scale have advantages in establishing the structure-property relationship. In recent years, great achievements have been made in electrochemical energy storage and electrocatalysis that allow the evolution and kinetics of electrodes to be understood by employing single-particle measurements. This concept aims to provide an overview of the update of single-particle measurements in related electrochemical processes. Furthermore, the challenges and prospects for the development and application of single-particle measurements are also discussed., (© 2022 Wiley-VCH GmbH.)

Rechargeable aluminum-ion batteries have attracted significant attention as candidates for next-generation energy storage devices owing to their high theoretical capacity, safe performance, and abundance of raw materials. Al metal is the best option as the negative electrode, while its issues such as dendrite growth and corrosion accompanying hydrogen evolution in ionic liquid electrolyte have been seriously overlooked. Understanding the electrochemical mechanism of the surface evolution behavior of Al metal is a vital pathway for solving these issues. Kinetic parameters and electrode structure are the two key parameters that affect the surface evolution behavior of Al negative electrodes. Herein, the qualitative relationship between the kinetic parameters and surface evolution behavior of the Al negative electrode was established through a combination of in-situ optical technology and multi-physical field numerical simulation method. The key kinetic parameters, including ion concentration and transfer coefficient, exhibited different laws of influence on the surface evolution behavior, such as dendrite growth and corrosion. The electrochemical mechanism on the surface evolution was explored to guide the optimization design of Al-ion batteries. Based on the coupling design of the electrode structure and kinetic parameters, a highly stable porous aluminum structure composed of Al powder with a particle size of 100 μm was constructed to obtain highly stable and high-performance aluminum-ion batteries. This method provides new sight into the design of high-performance aluminum-ion batteries., (© 2022 Wiley-VCH GmbH.)

Characterizing microscale single particles directly is requested for dissecting the performance-limiting factors at the electrode scale. In this work, we build a single-particle electrochemical setup and develop a physics-based model for extracting the solid-phase diffusion coefficient (D s ) and exchange current density (i 0 ) from electrochemical impedance measurements. We find that the carbon coating on the LiNi 1/3 Mn 1/3 Co 1/3 O 2 surface enhances i 0 . In addition, D s and i 0 decay irreversibly by ≈25 % and ≈10 %, respectively, when the cutoff charge voltage increases from 4.3 V to 4.4 V. Moreover, we correlate intrinsic parameters of single particles with the performance of porous electrodes. Porous electrodes assembled with active particles with higher i 0 values deliver a greater capacity and faster capacity fade. The methods developed in this combined experimental and theoretical work can be useful in correlating the single-particle scale and porous-electrode scale for other similar systems., (© 2022 Wiley-VCH GmbH.)

An ultrafast rechargeable multi-ions battery is presented, in which multi-ions can electrochemically intercalate into graphite layers, exhibiting a high reversible discharge capacity of ≈100 mAh g -1 and a Coulombic efficiency of ≈99% over hundreds of cycles at a high current density. The results may open up a new paradigm for multi-ions-based electrochemical battery technologies and applications., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)