In Situ Gelation of a 1,3-Dioxolane Dual-Permeable Porous Tandem Framework with Excellent Interfacial Stability to Power Long-Cycling Solid-State Lithium Metal Batteries

Abstract

Ceramic Li1.3Al0.3Ti1.7(PO4)3 (LATP) with high ionic conductivity and stability in ambient atmosphere is considered to be potent as a solid-state electrolyte of solid-state lithium metal batteries (SSLMBs), but its huge interfacial impedance with electrodes and the unwanted Ti4+-mediated reduction reaction caused by the lithium (Li) metal anode greatly limit its application in LMBs. Herein, a composite polymer electrolyte (CPET) was integrated by in situ gelation of dual-permeable 1, 3-dioxolane (DOL) in the tandem framework composed of the commercial cellulose membrane TF4030 and a porous three-dimensional (3D) skeleton-structured LATP. The in situ gelled DOL anchored in the tandem framework ensured nice interfacial contact between the as-prepared CPET and electrodes. The introduction of the porous 3D LATP endowed CPET the increased lithium-ion migration number (tLi+ ) of 0.70, a wide electrochemical stability window (ESW) of 4.86 V, and a high ionic conductivity of 1.16 × 10–4 S cm–1 at room temperature (RT). Meanwhile, the side reaction of the LATP/Li metal was adequately restrained by inserting TF4030 between the porous LATP and Li anode. Profiting from the superb interfacial stability and the enhanced ionic transport capacity of CPET, Li/Li batteries based on the optimal CPET (CPET2) cycled over 2000 h at 20∼30 °C smoothly. Moreover, solid-state LiFePO4 (LFP)/Li with CPET2 exhibited excellent electrochemical performance with a capacity retention ratio of 72.2% after 400 cycles at 0.5C. This work offers an integrated strategy to guide the fabrication of a highly conductive solid electrolyte and a stable interface design for high-performance SSLMBs.

In Situ Polymerization Derived from PAN-Based Porous Membrane Realizing Double-Stabilized Interface and High Ionic Conductivity for Lithium-Metal Batteries

“…The calculated ion conductivities of PDOL-PAN­(SN/LLZTO)-PDOL CSE are 1.93 × 10 –3 S cm –1 (RT) and 2.5 × 10 –3 S cm –1 (60 °C), respectively. The superior ion transport capacity of PDOL-PAN­(SN/LLZTO)-PDOL is believed to benefit significantly from the structural nature of the CSE, i.e., the 3D interconnected transportation channels …”

Ultralong Cycling and Interfacial Regulation of Bilayer Heterogeneous Composite Solid-State Electrolytes in Lithium Metal Batteries

“…SSEs are mainly categorized into inorganic ceramic electrolytes, organic polymer electrolytes, and composite solid-state electrolytes (CSE). Inorganic ceramic electrolytes, such as LLZO, , LLTO, and LAGP, , generally exhibit high room-temperature ionic conductivity and good mechanical strength, but poor interfacial contact at the electrolyte–electrodes results in high interfacial resistance, which hinders Li + transport. , In contrast, organic polymer electrolytes possess a relatively low elastic modulus and sufficient interfacial contact with the electrode compared to other materials, but their high crystallinity at room temperature limits the Li + transport along the polymer chain segments, which makes it difficult to meet the practical requirements. − In comparison to the inherent disadvantages of inorganic ceramic and organic polymer electrolytes, CSE, which combines their advantages, is considered the most promising candidate for the next generation of solid-state electrolytes. , Typically, PEO is widely regarded as an ideal polymer matrix due to its high flexibility, easy processing, and high solubility of lithium salts . However, PEO’s high crystallinity at low temperatures restricts chain segment movement, resulting in a relatively low ionic conductivity (<10 –5 –10 –6 S/cm) .…”