Phase‐Changeable Dynamic Conformal Electrode/electrolyte Interlayer enabling Pressure‐Independent Solid‐State Lithium Metal Batteries

Abstract

Lithium‐metal‐based solid‐state batteries (Li‐SSBs) are one of the most promising energy storage devices due to their high energy densities. However, under insufficient pressure constraints (<MPa‐level), Li‐SSBs usually exhibit poor electrochemical performances owing to the continuous interfacial degradation between the solid‐state electrolyte (SSE) and electrodes. Herein, a phase‐changeable interlayer is developed to construct the self‐adhesive and dynamic conformal electrode/SSE contact in Li‐SSBs. The strong adhesive and cohesive strengths of the phase‐changeable interlayer enable Li‐SSBs to resist up to 250 N pulling force (=1.9 MPa), affording Li‐SSBs ideal interfacial integrality even without extra stack pressure. Remarkably, this interlayer exhibits a high ionic conductivity of 1.3 × 10−3 S cm−1, attributed to the shortened steric solvation hindrance and optimized Li+ coordination structure. Furthermore, the changeable phase property of the interlayer endows Li‐SSBs with a healable Li/SSE interface, accommodating the stress–strain evolution of the lithium metal and constructing the dynamic conformal interface. Consequently, the contact impedance of the modified solid symmetric cell exhibits a pressure‐independent manner and does not increase over 700 h (0.2 MPa). The LiFePO4 pouch cell with the phase‐changeable interlayer shows 85% capacity retention after 400 cycles at a low pressure of 0.1 MPa.

Eliminating Li Dendrites in PEO-Based Polymer Solid Electrolytes by Doping with SbF3

“…In comparison to the reported configuration of SPEs-based ASSLMBs in Figure a, b, Table S5, Supporting Information, the electrochemical performance of ASSLMBs utilizing PLS1 electrolytes in our study is at the forefront, presenting a promising avenue for practical PEO-based ASSLMBs. ,− Specifically, the Li effect of the Li dendrites is utilized to fill the SbF 3 nanoparticles into the solid electrolyte to phagocytic and anchor the Li dendrites while completing the transformation of the stable SEI layer . It has been observed that SbF 3 nanoparticles can undergo lithiation with the neighboring Li dendrites, which possess a robust electron transport capability .…”

“…Electrochemical performance comparison with the literature. ,− (a) Li–Li symmetric cells cycle time at 0.1 mA cm –2 and (b) the energy density of the full cells and the corresponding C-rate (1C ≈ 170 mA g –1 ).…”

Tuning the Covalent Coupling Degree between the Cathode and Electrolyte for Optimized Interfacial Resistance in Solid-State Lithium Batteries

“…As shown in Figure S2, LFP exhibits two peaks in the O 1s spectrum. One peak located at a high binding energy of around 531.5 eV relates to −PO 4 and hydroxyl groups on the surface of LFP, while another one at a lower binding energy of about 529.5 eV is attributed to lattice O of LFP. ,, Notably, the peak at 529.5 eV disappeared in the O 1s spectrum of F-LFP-LGD, F-LFP-MGD, and F-LFP-HGD in Figure S2. Meanwhile, new peaks associated with C–O (533.5 eV) and Si–O (532.6 eV) originating from the grafted KH570 are observed, further confirming the hydrolysis reaction between KH570 and LFP. , Furthermore, the ratio of the peak density of Si–O progressively increases with increasing reaction time, suggesting that surface chemistry altered from hydroxyl groups to targeted CC groups in varying degrees, leading to gradient distribution of functional groups on the surface of the cathode.…”

“…One peak located at a high binding energy of around 531.5 eV relates to −PO 4 and hydroxyl groups on the surface of LFP, while another one at a lower binding energy of about 529.5 eV is attributed to lattice O of LFP. 34,36,37 Notably, the peak at 529.5 eV disappeared in the O 1s spectrum of F-LFP-LGD, F-LFP-MGD, and F-LFP-HGD in Figure S2. Meanwhile, new peaks associated with C−O (533.5 eV) and Si−O (532.6 eV) originating from the grafted KH570 are observed, further confirming the hydrolysis reaction between KH570 and LFP.…”

Polymer-based electrolytes for solid-state lithium batteries with a wide operating temperature range

“…[64][65][66][67] Quasi-solid polymer electrolytes prepared by in situ polymerization can obtain conformal interface contacts, thus reducing the interfacial resistance and realizing rapid charge transfer at interfaces. 68 Ciucci and coworkers prepared a flexible and highly conductive DOLbased quasi-solid polymer electrolyte, obtaining an integrated battery structure and outstanding ionic conductivity of 1 mS cm À1 @À30 1C. 39 The formed polymer-dominated SEI provided rapid Li + transport and superior interfacial stability by inhibiting parasitic reactions between the MP and the Li metal anode.…”