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Gel polymer electrolytes (GPEs) hold great promise for the practical application of lithium metal batteries. However, conventional GPEs hardly resists lithium dendrites growth and maintains long‐term cycling stability of the battery due to its poor mechanical performance. Inspired by the slide‐ring structure of polyrotaxanes (PRs), herein we developed a dynamic slide‐crosslinked gel polymer electrolyte (SCGPE) with extraordinary stretchability of 970.93 % and mechanical strength of 1.15 MPa, which is helpful to buffer the volume change of electrodes and maintain mechanical integrity of the battery structure during cycling. Notably, the PRs structures can provide fast ion transport channels to obtain high ionic conductivity of 1.73×10−3 S cm−1 at 30 °C. Additionally, the strong polar groups in SCGPE restrict the free movement of anions to achieve high lithium‐ion transference number of 0.71, which is favorable to enhance Li+ transport dynamics and induce uniform Li+ deposition. Benefiting from these features, the constructed Li|SCGPE‐3|LFP cells exhibit ultra‐long and stable cycle life over 1000 cycles and high‐capacity retention (89.6 % after 1000 cycles). Even at a high rate of 16 C, the cells deliver a high capacity of 79.2 mAh g−1. The slide‐crosslinking strategy in this work provides a new perspective on the design of advanced GPEs for LMBs. [ABSTRACT FROM AUTHOR]

All‐solid‐state lithium metal batteries (ASSLMBs) hold great promise for the development of next‐generation high‐safety, high‐energy‐density lithium batteries, but still face the challenges of lithium dendrite growth and thickness. Herein, the ultrathin PEO‐based composite solid polymer electrolyte (denoted as PAL) supported by a low‐density self‐supporting aramid nanofiber (ANF) aerogel framework is developed. The ANF aerogel obtained by a novel CO2‐assisted induced self‐assembly method has a well‐designed bilayer structure with double cross‐linking degree. Benefiting from the intermolecular interaction between ANFs and PEO, the PAL achieves an ultrathin thickness (20 µm) with excellent thermal stability and mechanical strength. Meanwhile, due to the modulation of ionic pathways by the functionalized ANF, the PAL achieves uniform lithium deposition without dendrites, resulting in stable long cycling (1400 h) for symmetric cells. Consequently, the Li|PAL|LiFePO4 (LFP) cell has excellent long‐term cycling stability (1 C, >700 cycles, Coulombic efficiency > 99.8%) and fast charge/discharge performance (rate, 10 C). More practically, the Li|PAL|LFP cell achieves an energy density of 180 Wh kg−1 due to the ability to match a high‐loading (8 mg cm−2) cathode. Furthermore, the double‐layer Li|PAL|LFP pouch cell demonstrates excellent flexibility and safety in cycling and abuse tests. [ABSTRACT FROM AUTHOR]

The unstable lithium (Li)/electrolyte interface, causing inferior cycling efficiency and unrestrained dendrite growth, has severely hampered the practical deployment of Li metal batteries (LMBs), particularly in carbonate electrolytes. Herein, we present a robust approach capitalizing on a dynamic supramolecular elastomer (DSE) interface layer, which is capable of being reduced with Li metal to spontaneously form strong Li + ion-dipole interaction, thereby enhancing interfacial stability in carbonate electrolytes. The soft phase in the DSE structure enables fast Li + transport via loosely coordinated Li + -O interaction, while the hard phase, rich in electronegative lithiophilic sites, drives the generation of fast-ion-conducting solid electrolyte interface components, including Li 3 N and Li 2 S. Furthermore, the dynamically resilient DSE network composed of soft and hard phases protects Li anodes from electrolyte corrosion and accommodates volume changes during cycling. All features of the DSE layer synergistically facilitate uniform Li + deposition and suppress Li dendrite propagation, ensuring a stable and dendrite-free Li anode. Consequently, the symmetric Li||Li cell incorporating the DSE layer achieves cycling stability exceeding 6000 h under 1 mA cm -2 and 1 mA h cm -2 conditions. Furthermore, full cell pairing DSE/Li anode with LiFePO 4 (LFP) or high-voltage LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) cathodes exhibits high-efficiency Li deposition and cycling stability, even under constrained conditions of limited Li (40 μm) and ultrahigh loading NMC811 cathode (21.5 mg cm -2 ). This study underscores the effectiveness of the ion-dipole interaction-enabled DSE network in developing stable, high-energy-density LMBs.