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Browse AllWith the growing global demand for sustainable energy and high-performance mobile devices, lithium metal solid-state batteries (LMBs) have emerged as a research hotspot in the field of energy storage due to their exceptional high energy density and significant safety advantages. However, the growth of lithium dendrites and their penetration through the solid electrolyte remain key issues leading to battery short-circuiting and failure. To date, there has been a lack of effective in situ research methods to reveal the failure mechanisms, which has severely restricted the commercialization of LMBs. This study innovatively employs in situ electrochemical impedance spectroscopy (EIS) to investigate lithium plating behavior in symmetric cells during critical current density (CCD) tests under room temperature and elevated temperature conditions. By analyzing characteristic signals at 1 MHz, this study presents the in situ impedance changes at the grain boundaries and interfaces of the
The State of Charge (SOC) is a key parameter for measuring the remaining capacity of new energy vehicle batteries. It not only directly reflects the driving range of the vehicle but also plays an indispensable role in ensuring operational safety and extending battery lifespan. Accurate estimation of SOC provides strong support for the safe and reliable operation of electric vehicles. During the charging and discharging process of lithium iron phosphate batteries, the intercalation and deintercalation of lithium ions cause deformation of the electrode's lattice structure, leading to the expansion and contraction of the electrode volume. This, in turn, exerts stress on the limited internal space of the battery, which is mainly manifested as changes in battery pressure monitored by sensors. To address the issues of insufficient information and low estimation accuracy associated with the use of electrical signals in traditional data-driven methods, this study introduces pressure
Sodium-ion batteries (SIBs) are becoming a strong candidate for large-scale energy storage applications due to their cost-effectiveness and abundant sodium resource reserves. Ether solvents have advantages such as excellent low-temperature performance and good reduction stability. However, poor oxidation stability limits the use of ether-based electrolytes, which need to be addressed urgently. In this study, 1 M sodium tetrafluoroborate (NaBF4) and 0.05 M sodium difluoro(oxalato)borate (NaDFOB) were added in tetraethylene glycol dimethyl ether (G4), which is named “BDG4”. BDG4 electrolyte can promote the formation of cathode electrolyte interface (CEI) layers containing NaF and B─O/B─Na inorganic components on the surface of the cathode. The dense CEI layers can prevent the solvent from undergoing oxidation reactions. Therefore, thanks to the lower highest occupied molecular orbital (HOMO) energy level of G4 and its close coordination structure with Na+, the electrolyte has a high
Reliable monitoring of the internal state of lithium-ion batteries (LIBs) is crucial for mitigating potential safety hazards. The incorporation of a reference electrode (RE) within the battery constitutes a vital approach for achieving single-electrode monitoring and understanding changes in electrode state during cycling. Among these, the lithium-copper reference electrode (Li-Cu RE) is particularly cost-effective and straightforward to prepare, being fabricated by depositing lithium onto a copper wire. However, Li-Cu RE exhibits a relatively short effective lifespan during long-term cycling, thereby limiting its practical application. In this work, based on a self-fabricated three-electrode single-layer pouch cell, the microstructural changes before and after failure of the Li-Cu RE were characterized and analyzed, revealing its failure evolution process. Post-failure microstructures observations exhibit marked porosity in the electrode, attributed to substantial depletion of surface