In Situ‐Formed LiF‐Rich Multifunctional Interfaces toward Stable Li₁₀GeP₂S₁₂‐Based All‐Solid‐State Lithium Batteries

Abstract

Li10GeP2S12 (LGPS) solid electrolyte with extremely high ionic conductivity is a promising candidate for all‐solid‐state lithium batteries. However, continued LGPS reduction at Li/LGPS interface is huge challenge. Thus, developing a simple and effective strategy to improve Li/LGPS interfacial stability is highly urgent. Herein, LiF‐rich multifunctional interfaces on Li metal (Li@LiF), consisting of three functional components of LiF, carbon particles, and thin CF bond top‐layer, are in situ constructed on the Li metal surface by spontaneous reaction between Li metal and poly(tetrafluoroethylene) at room temperature. LiF, as the main component, significantly suppresses the interfacial reaction due to low electronic conductivity and promotes smooth lithium plating on the Li metal surface arising from high interfacial energy against Li. Meanwhile, carbon particles with excellent Li+ affinity and thin strong polar CF bond top‐layer enable homogenous Li+ flux as well as fast Li+ migration across the LiF‐rich interface, respectively. Consequently, the LGPS‐based symmetric lithium cell possesses significantly prolonged cycling stability and increased critical current density. The LGPS‐based all‐solid‐state lithium cells employing LiCoO2 cathode and Li@LiF anode exhibit excellent rate capability and impressive cycling stability, achieving a high capacity retention of 80.9% over 300 cycles at 0.1 C under 25 °C.

Electrode Protection and Electrolyte Optimization via Surface Modification Strategy for High‐Performance Lithium Batteries

“…Shen et al. [ 223 ] built an LiF‐rich layer on Li anode surface to improve the interfacial stability between Li and LGPS via a spontaneously reaction of lithium and poly(tetrafluoroethylene). In addition, Chen et al.…”

“…The enhanced contact area and unique structure decreased the local current density and generated stable interphase. Shen et al [223] built an LiF-rich layer on Li anode surface to improve the interfacial stability between Li and LGPS via a spontaneously reaction of lithium and poly(tetrafluoroethylene). In addition, Chen et al [224] adopted the ultrathin poly[2,3-bis(2,2,6,6tetramethylpiperidine-N-oxycarbonyl)-norbornene](PTNB) polymer coating layer on Li metal anode to avoid the structure failure of LATP when it contacted to Li metal.…”

Solid Electrolyte Interphase Architecture for a Stable Li‐electrolyte Interface

“…Zhang et al developed a LiF-rich multifunctional interphase with a thickness of around 3 μm on Li metal anode of LGPSbased SSLMBs. [162] The artificial interphase consisted of LiF, amorphous carbon particles, and CÀ F bond. The LiF could block the synergistic effect of the composite SSEs and the coated artificial SEI layer.…”

“…Zhang et al. developed a LiF‐rich multifunctional interphase with a thickness of around 3 μm on Li metal anode of LGPS‐based SSLMBs [162] . The artificial interphase consisted of LiF, amorphous carbon particles, and C−F bond.…”

LiAlO2-Modified Li Negative Electrode with Li10GeP2S12 Electrolytes for Stable All-Solid-State Lithium Batteries

“…17 So far, constructing a protective layer is a viable strategy to strengthen the Li 10 GeP 2 S 12 /lithium metal interface. For example, research studies have demonstrated an improved interface stability by introducing Li 3 PO 4 , 18 LiF, 19 and BN 20 layers at the Li 10 GeP 2 S 12 /lithium metal interface. In addition, alloys such as Li−Ag 21 and Li−Mg 22 have also been used as a buffer layer to provide effective protection for Li 10 GeP 2 S 12 .…”