Self-Sacrificed Interface-Based on the Flexible Composite Electrolyte for High-Performance All-Solid-State Lithium...

All-solid-state lithium batteries (ASSLBs) are considered a promising alternative to conventional lithium-ion batteries due to their enhanced safety and energy density. Ceramic electrolytes are favored for their high ionic conductivity and wide electrochemical stability. However, the interface between ceramic and polymeric components remains a significant obstacle. This interfacial impedance limits performance and cycle life. While prior research has shown the potential of ceramic electrolytes, the challenge of achieving stable and well-wetted interfaces persists. No prior work has resolved the issue of interfacial resistance without compromising mechanical stability. This gap motivated the development of a new composite electrolyte design. Researchers have explored various strategies, such as surface coatings and interlayers, but none have fully addressed the dual requirements of conductivity and mechanical strength. The need for a flexible yet stable interface remains unmet. This study introduces a novel approach to interface engineering in ASSLBs.

The aim of this study is to address the interfacial impedance issue in all-solid-state lithium batteries by designing a composite electrolyte with a self-sacrificed interface. The researchers propose a flexible composite electrolyte composed of LAGP and PPC to enhance interfacial contact. This approach is intended to reduce both interfacial and bulk resistance while maintaining mechanical stability. The study focuses on the LiFePO4/Li battery system to evaluate performance. The researchers hypothesize that the amorphous layer formed by the PPC component will improve wetting and reduce resistance. The study also explores the role of the LiF layer in preventing dendrite growth. The motivation stems from the need for a stable and safe battery design. The researchers aim to demonstrate a feasible solution to overcome the interface challenges in ASSLBs.

The researchers developed a flexible composite electrolyte using Li1.5Al0.5Ge1.5(PO4)3 (LAGP) and 30% poly(propylene carbonate) (PPC). The composite was fabricated through a solution-casting method. The LAGP provided mechanical strength and ionic conductivity. The PPC component was designed to form a self-sacrificed interface. The electrolyte was tested in a LiFePO4/Li battery configuration. The interfacial resistance was measured using electrochemical impedance spectroscopy. The battery performance was evaluated at 55 °C over 100 cycles. The researchers also analyzed the microstructure of the interface using scanning electron microscopy. The study compared the performance of the composite electrolyte to conventional designs. The amorphous state of the PPC-derived layer was confirmed through X-ray diffraction.

The composite electrolyte achieved a discharge specific capacity of 151 mA h g-1 at 0.05 C. The battery retained 92.3% of its capacity after 100 cycles at 55 °C. The interfacial resistance was significantly reduced due to the amorphous layer formed by the PPC component. The LAGP component provided mechanical stability and ionic conductivity. The LiF layer prevented the growth of lithium dendrites. The composite electrolyte demonstrated long cycle life and high safety. The self-sacrificed interface improved the wettability between the electrolyte and electrode. The study confirmed the effectiveness of the flexible composite design in reducing resistance. The combination of ceramic and polymer components enhanced overall performance. The results suggest that this approach is a viable solution for interface issues in ASSLBs.

The study demonstrates that the self-sacrificed interface in the flexible composite electrolyte reduces interfacial resistance in ASSLBs. The combination of LAGP and PPC components provides both mechanical strength and ionic conductivity. The amorphous layer formed by the PPC component improves wettability and reduces resistance. The LiF layer contributes to dendrite suppression and long cycle life. The researchers propose that this approach offers a feasible solution to interface issues in ASSLBs. The results suggest that the composite electrolyte design is effective for high-performance batteries. The study highlights the complementary advantages of ceramic and polymer materials. The authors suggest that this strategy could be applied to other battery systems. The findings support the potential of the flexible composite electrolyte for commercial applications. The study confirms the importance of interface engineering in ASSLBs.