Solid-state Battery Applications Research Articles

Liquid Metal Interlayer for Ultrastable Solid-State Sodium Metal Battery.

Solid-state sodium metal batteries have attracted wide attention due to their high energy density, remarkable safety, and abundant sodium resources. However, the growth of Na dendrites and poor interfacial contact between Na metal anode and Na3Zr2Si2PO12 (NZSP) solid-state electrolytes severely limit their practical application. Herein, a wettable liquid metal (GaIn) interlayer significantly reduces the interfacial resistance and avoids the formation of voids at the Na/NZSP interface. Moreover, the Ga4Na and NaIn alloys at the interface caused by the spontaneous reaction of GaIn with Na metal enhance the bond of NZSP with Na anode, which provides a continuous Na+ diffusion pathway and homogeneous Na+ flux to suppress Na dendrite growth. The symmetric cell can cycle stably for over 6500h at 0.05mA cm-2 and over 3000h at 0.1mA cm-2, with a critical current density of 0.8mA cm-2 at 25°C, and the interfacial resistance is significantly reduced to 21.6 Ω from 1095.1 Ω. The full cell coupled with NaNi1/3Fe1/3Mn1/3O2 also shows outstanding cycling performance, maintaining 85.1% capacity after 100 cycles at 0.5 C. This work demonstrates that the liquid metal interlayer has a large potential for the practical application of solid-state metal batteries.

Stabilizing electrode-electrolyte interface via crown ether-containing selective coating for dendrite-free Na-K anode-based solid-state sodium batteries

Sodium-potassium (Na-K) alloy is considered a promising anode material due to its liquid characteristics at room temperature. However, unstable interfaces and disastrous ion exchange between Na-K alloy anodes and solid-state Na electrolytes (SSNEs) have hindered further applications of solid-state Na batteries (SSNBs) based on Na-K anodes. In this work, a specially designed Na+/K+ selective gel coating with 15-crown 5-ether (15C5) is constructed on the beta-alumina solid electrolyte (BASE) to achieve a good match with Na-K anodes. The coordination of 15C5 with Na+ forms Na+-permeable complexes and affects the electrolyte solvation structure in the gel coating, resulting in the formation of solid electrolyte interfaces (SEIs) that lack K+ channels and are organically rich, which effectively inhibit the ion exchange and stabilize the interface. Benefitting from the selective coating, the cycling lifetime of the Na-K|Gel-BASE-Gel|Na-K symmetric cell reaches over 1000 h, and the Na-K|Gel-BASE-Gel|Na3V2(PO4)3 full cell exhibits great long-cycle stability and excellent rate performance at room temperature. This work extends the application of Na-K anodes and provides a suggestion for achieving high-performance SSNBs at room temperature.

In situ synthesis of cross-linking gel polymer electrolyte for lithium metal batteries

AbstractThe room temperature ionic conductivity of polyethylene oxide (PEO)-based polymer electrolytes is low, the electrochemical window is narrow, and the mechanical strength is relatively poor. In this work, a cross-linking gel-based solid composite polymer electrolyte (CG-SCPE) was synthesized by introducing electrochemically stable carbonate-based functional groups. The synthesized CG-SCPE presents excellent tensile strength (26 MPa) and a wide electrochemical stability window (> 4.5 V vs. Li/Li+). Meanwhile, the in situ polymerization method induced by thermal heating resulted in good compatibility between electrodes/electrolytes. In addition, the assembled LiNi0.5Co0.2Mn0.3O2/CG-SCPE/Li battery exhibited satisfactory electrochemical performance. Therefore, the gel polymer electrolyte CG-SCPE with cross-linking network provides the possibility for future application of safe and high-performance solid-state lithium metal batteries. The results indicate that the introduction of cross-linking framework can simultaneously improve the mechanical strength, thermal stability, and electrochemical performance of solid polymer electrolyte.

Fluorine-Doped Li7La3Zr2O12 Fiber-Based Composite Electrolyte for Solid-State Lithium Batteries with Enhanced Electrochemical Performance.

Garnet-based electrolytes with high ionic conductivity and excellent stability against lithium metal anodes are promising for commercial applications in solid-state lithium batteries (SSLBs). However, the further development of SSLBs is inhibited by issues such as low ionic conductivity and uncontrolled lithium dendrite growth. Herein, we report the synthesis of fluorine-doped Li7La3Zr2O12 (LLZO-F0.2) fibers by electrospinning and the subsequent calcination at high temperatures. The solid composite electrolyte with LLZO-F0.2 exhibits an ionic conductivity of 5.37 × 10-4 S cm-1 and a high lithium-ion transference number of 0.61 at room temperature. Meanwhile, it exhibits lower resistance and more uniform lithium metal stripping and deposition in symmetric cells. The full cell with LiFePO4 cathode exhibits excellent rate capability and cycling stability for 800 cycles at 0.5 C with a discharge specific capacity retention of 97.7%. This fluorine-doped fibrous garnet-type electrolyte provides a viable option for preparing high-performance SSLBs.

Percolating coordinated ion transport cells in polymer electrolytes to realize room-temperature solid-state lithium metal batteries

Polymer electrolytes, notable for their good mechanical properties, superior processability, and high electrochemical stability, are promising for high-energy-density lithium metal batteries. However, the ionic conduction of polymer electrolytes is seriously constrained by either the entanglement of polymer chains or binding of anions, particularly at ambient temperatures, making their practical application impossible. Herein, we employ a high-salt-concentration strategy with poly(vinylene carbonate) to construct a percolating network by linking coordinated ion transport cells. The cells, consisting of lithium-ion at the core surrounded by coordinated poly(vinylene carbonate), N,N-dimethylformamide, or incompletely bonded bis(trifluoromethanesulfonyl)imide, ensure an efficient coordination and de-coordination process for ion transport. Thus, a high rate of Li+ transport is realized, achieving an ionic conductivity of 0.82 mS cm−1 at 30 °C. Consequently, the formulated solid-state lithium metal batteries with the poly(vinylene carbonate) electrolyte enable superior stability in cycling under a wide temperature range (0–60 °C), high working voltage (4.5 V), and high mass load (>10 mg cm−2). This simple strategy for creating an ion-percolating network by linking coordinated ion transport cells not only offers new insights into understanding the mechanism for ion transport in polymer electrolytes but also paves the way for the application of solid-state lithium metal batteries.

Incorporating Sodium-Conductive Polymeric Interfacial Adhesive with Inorganic Solid-State Electrolytes for Quasi-Solid-State Sodium Metal Batteries.

Inorganic solid-state electrolytes have attracted enormous attention due to their potential safety, increased energy density, and long cycle-life benefits. However, their application in solid-state batteries is limited by unstable electrode-electrolyte interface, poor point-to-point physical contact, and low utilization of metallic anodes. Herein, interfacial engineering based on sodium (Na)-conductive polymeric solid-state interfacial adhesive is studied to improve interface stability and optimize physical contacts, constructing a robust organic-rich solid electrolyte interphaselayer to prevent dendrite-induced crack propagation and security issues. The interfacial adhesive strategy significantly increases the room-temperature critical current density of inorganic Na-ion conductors from 0.8 to 3.2mAcm-2 and markedly enhances the cycling performance of solid-state batteries up to 500 cycles, respectively. Particularly, the Na3V2(PO4)3-based full solid-state batteries with high cathode loading of 10.16mgcm-2 also deliver an excellent cycling performance, further realizing the stable operation of solid-state laminated pouch cells. The research provides fundamental perspectives into the role of interfacial chemistry and takes the field a step closer to realizing practical solid-state batteries.

Recent Progress on Dominant Sulfide-Type Solid-State Na Superionic Conductors for Solid-State Sodium Batteries.

Over the past decade, solid-state batteries have garnered significant attentions due to their potentials to deliver high energy density and excellent safety. Considering the abundant sodium (Na) resources in contrast to lithium (Li), the development of sodium-based batteries has become increasingly appealing. Sulfide-based superionic conductors are widely considered as promising solid eletcrolytes (SEs) in solid-state Na batteries due to the features of high ionic conductivity and cold-press densification. In recent years, tremendous efforts have been made to investigate sulfide-based Na-ion conductors on their synthesis, compositions, conductivity, and the feasibility in batteries. However, there are still several challenges to overcome for their practical applications in high performance solid-state Na batteries. This article provides a comprehensive update on the synthesis, structure, and properties of three dominant sulfide-based Na-ion conductors (Na3PS4, Na3SbS4, and Na11Sn2PS12), and their families that have a variety of anion and cation doping. Additionally, the interface stability of these sulfide electrolytes toward the anode is reviewed, as well as the electrochemical performance of solid-state Na batteries based on different types of cathode materials (metal sulfides, oxides, and organics). Finally, the perspective and outlook for the development and practical utilization of sulfide-based SE in solid-state batteries are discussed.

A general strategy for all-solid-state batteries with agglomeration-free and high conductivity achieved by improving the interface compatibility of fillers and polymer matrix

Composite solid electrolytes (CSEs) composed of polymer matrix and inorganic fillers show considerable potential for applications in all-solid-state lithium (Li) metal batteries. However, challenges such as fillers agglomeration and low lithium ion transference number (tLi+) remain significant obstacles to the practical application of CSEs. Herein, a general strategy of graft polymerization on the fillers surface to modulate the interface compatibility with the polymer matrix is proposed, and CSEs are prepared to verify the feasibility. The microstructure and composition of the surface coating of the fillers are analyzed, with subsequent studies of the fillers distribution within the CSEs confirming the improved interface compatibility. The enhancement of interface compatibility facilitates uniform dispersion of fillers, thereby greatly improving the utilization of fillers. CSEs exhibits high ionic conductivity (0.163 mS·cm−1 at 30 °C) and tLi+ (0.77), which gives the battery excellent rate performance and cycle stability. Therefore, chemical grafting of polymer onto the fillers surface to enhance the interface compatibility with the polymer matrix represents a promising strategy for the practical application of solid-state batteries.

Conformation inversion of succinonitrile towards long-life solid-state lithium metal batteries

Solid-state lithium metal batteries are considered as the next-generation energy storage devices, but their application is significantly hindered by poor interfacial compatibility between Li anodes and solid-state electrolytes, especially for succinonitrile (SN) based electrolyte. Herein, this issue is addressed by a conformation inversion strategy via introducing a PE separator grafted with poly-(lithium 2-acrylamido-2-methylpropanesulfonic acid) (PAMPSLi) brushes into a SN-based electrolyte. The PAMPSLi brushes inverse the conformation of SN molecules through the multiple interactions between −SO3Li and cyanide groups, alleviating the corrosion reactions of SN on Li anodes. Significantly, the PAMPSLi brushes regulate Li+ transport pathway with the inversed SN molecules at the anode/electrolyte interface to achieve uniform Li deposition. Notably, the PAMPSLi brushes contribute to a solid electrolyte interphase (SEI) film rich in LiF and Li3N. Consequently, the solid-state Li||LiFePO4 batteries with the resulting electrolyte exhibit a specific discharge capacity of 115.0 mAh/g and a considerably long cycle life of 1500 cycles at 3 C. A pouch cell with a high-loading LiFePO4 cathode (18 mg cm−2) also exhibits a high areal capacity and superior safety. This study provides a novel strategy for achieving a stable electrolyte/anode interface in SN-based electrolytes, which facilitates the practical application of solid-state batteries with long life and high energy density.

Garnet-based solid state batteries benefitting from an ionic/electronic mixed conductive interface constructed by lithiation of porous FeS2

Garnet-based solid-state lithium metal batteries are considered as the potential candidates for the next-generation energy storage systems due to their high energy density, wide operating temperature, and high safety. However, the poor wettability of the lithium metal anode/garnet interface, the large interface resistance, and the risk of lithium dendrites growing and even penetrating electrolytes during cycling limit the practical application of garnet-based solid-state lithium metal batteries. In this work, a porous network FeS2 with an amorphized structure is prepared by using the solvothermal method and used as the Li/garnet interface modification layer. The porous FeS2 can be in situ converted into a Li2S/Fe mixed conductive layer by the thermal lithiation of molten metallic lithium. This mixed conductive layer can significantly reduce the interface resistance, ensure the close contact between Li and garnet, and inhibit the growth of lithium dendrites. The interface resistance of the modified Li/FeS2-LLZTO (LLZTO is Li6.5La3Zr1.5Ta0.5O12) interface at 60 °C is as small as 15.20 Ω cm2. The ionic conductivity of fully lithiated FeS2 is estimated to be 1.58 × 10−6 S cm−1 at room temperature. The Li/FeS2-LLZTO/Li symmetrical cell can cycle stably for more than 400 h at a high current density of 400 μA cm−2, with the voltage polarization of only about 25 mV, and can withstand a larger current density of 600 μA cm−2 without the polarization exceeding 50 mV. These results demonstrate the feasibility of in situ lithiation of porous iron sulfide into a mixed ion/electron conductive layer as a solid-state garnet interface modification strategy and provide the new interface method for the development of high-performance solid-state lithium metal batteries.

A Star-StructuredPolymer Electrolyte for Low-Temperature Solid-State Lithium Batteries.

Solid-state polymer lithium metal batteries (SSLMBs) have attracted considerable attention because of their excellent safety and high energy density. However, the application of SSLMBs is significantly impeded by uneven Li deposition at the interface between solid-state electrolytes and lithium metal anode, especially at a low temperature. Herein, this issue is addressed by designing an agarose-based solid polymer electrolyte containing branched structure. The star-structured polymer is synthesized by grafting poly (ethylene glycol) monomethyl-ether methacrylate and lithium 2-acrylamido-2-methylpropanesulfonate onto tannic acid. The star structure regulates Li-ion flux in the bulk of the electrolyte and at the electrolyte/electrodeinterfaces. This unique omnidirectional Li-ion transportation effectively improves ionic conductivity, facilitates a uniform Li-ion flux, inhibits Li dendrite growth, and alleviates polarization. As a result, a solid-state LiFePO4||Li battery with the electrolyte exhibits outstanding cyclability with a specific capacity of 134 mAh g-1 at 0.5C after 800 cycles. The battery shows a high discharge capacity of 145 mAh g-1 at 0.1 C after 200 cycles, even at 0°C. The study offers a promising strategy to address the uneven Li deposition at the solid-state electrolyte/electrode interface, which has potential applications in long-life solid-state lithium metal batteries at a low temperature.

Silica-Poly(Vinyl Alcohol) Composite Aerogel: A Promising Electrolyte for Solid-State Sodium Batteries.

The transition from fossil fuels is in part limited by our inability to store energy at different scales. Batteries are therefore in high demand, and we need them to store more energy, be more reliable, durable and have less social and environmental impact. Silica-poly(vinyl alcohol) (PVA) composite aerogels doped with sodium perchlorate were synthesized as novel electrolytes for potential application in solid-state sodium batteries. The aerogels, synthesized by one-pot synthesis, are light (up to 214 kg m-3), porous (~85%), exhibit reduced shrinkage on drying (up to 12%) and a typical silica aerogel microstructure. The formation of a silica network and the presence of PVA and sodium perchlorate in the composite were confirmed by FTIR and TGA. The XRD analysis also shows that a predominantly amorphous structure is obtained, as crystalline phases of polymer and salt are present in a very reduced amount. The effects of increasing polymer and sodium salt concentrations on the ionic conductivity, assessed via electrochemical impedance spectroscopy, were studied. At a PVA concentration of 15% (w/w silica precursors), the sodium conduction improved significantly up to (1.1 ± 0.3) × 10-5 S cm-1. Thus, this novel material has promising properties for the envisaged application.

Realizing the dendrite-free sulfide-based all-solid-state Li metal battery by surface design

Although the ultrahigh ionic conductivity of sulfide-type solid electrolytes is comparable to that of liquid electrolytes, the low critical current density (CCD) limits the practical application of solid-state lithium (Li) metal batteries. The insufficient Li0 self-diffusion in solid Li leads to the voids that form at the interface at a large stripping current density, which results in interface contact loss and the increase of local current density. Herein, an artificial hybrid interphase layer dominated by Li3Sb and LiF was constructed on the Li surface to explore the Li plating/stripping behavior at the Li/Li6PS5Cl interface. The Li3Sb alloy provides a fast Li0 diffusion channel to avoid the interfacial voids formation and current focusing, while the electrically insulated LiF acts an electron blocking shield at the Li/Li6PS5Cl interface. Consequently, the symmetric cells reveal a significantly increased CCD of 1.8 mA cm−2 and a stable Li plating/stripping for 1472 h with a high current density of 2 mA cm−2 at 50 °C. Moreover, the all-solid-state Li-SPAN cell with Li3Sb/LiF interphase exhibits good capacity retention of 83.2 % after 120 cycles at 0.5 C, and it also delivers a superior rate performance of 400 mAh g−1 at 5C. The construction of lithium-alloy interphase is a promising alternative to solid-state lithium battery applications.

Covalent Organic Framework Enhanced Solid Polymer Electrolyte for Lithium Metal Batteries.

High ionic conductivity, outstanding mechanical stability, and a wide electrochemical window are the keys to the application of solid-state lithium metal batteries (LMBs). Due to their regular channels for ion transport and tailored functional groups, covalent organic frameworks (COFs) have been applied to solid electrolytes to improve their performance. Herein, we report a flexible polyethylene oxide-COF-LZU1 (abbreviated as PEO-COF) electrolyte membrane with a high lithium ion transference number and satisfactory mechanical strength, allowing for dendrite-free and long-time cycling for LMBs. Benefiting from the interaction between bis(triflfluoromethanesulonyl)imide anions (TFSI-) and aldehyde groups in COF-LZU1, the Li+ transference number of the PEO-5% COF-LZU1 electrolyte reached up to 0.43, much higher than that of neat PEO electrolyte (0.18). Orderly channels are conducive to the homogenous Li-+ deposition, thereby inhibiting the lithium dendrites. The assembled LiFePO4|PEO-5% COF-LZU1/Li cells delivered a discharge specific capacity of 146 mAh g-1 and displayed a capacity retention of 80% after 200 cycles at 0.1 C (60 °C). The Li/Li symmetrical cells of the PEO-5% COF-LZU1 electrolyte presented a longer working stability at different current densities compared to that of the PEO electrolyte. Therefore, the enhanced comprehensive performance of the solid electrolyte shows potential application prospects for use in LMBs.

Enhanced electrical performance of LiMnPO4 by carbon coating for solid-state battery applications

High-energy ball milling was employed to fabricate LiMnPO4 coated with varying carbon ratios (3%wt, 7%wt, and 10%wt), using glucose as a carbon source. The process involved pre-milling of LiMnPO4 precursors, followed by granulation through high-energy ball milling at 270 rpm for 2 h, and subsequent calcination at 700 °C without an inert gas flow. XRD analysis discerned the phases and structure of LiMnPO4, confirming the successful attainment of a single-phase LiMnPO4 without impurities. Rietveld refinement of the XRD data elucidated the crystallographic details, affirming the material's orthorhombic olivine structure with precise lattice parameters, thereby underpinning the structural integrity essential for electrochemical applications. FE-SEM analysis revealed uniformly distributed semi-sphere particles, with sizes ranging from 130 nm for LM to 183 nm for LM-10%C. FTIR analysis delineated the internal modes of vibration in the olivine structure and verified the presence of carbon on the powder surface. Electrical measurements conducted within the frequency range of 20 Hz–100 kHz demonstrated an increase in electrical conductivity with an escalation in carbon concentration, ranging from 31 μΩ−1m−1 to 75 μΩ−1m−1 for 0%C and 10%C, respectively. A temperature-dependent study spanning 30–160 °C revealed stable electrical conductivity behavior for the samples, with a marginal increase observed at elevated temperatures.

Ce doped UiO-66(Hf) electrolyte for all-solid-state lithium metal batteries

Solid electrolytes have garnered significant attention as promising candidates for all-solid-state batteries due to their excellent safety, and cycling stability. However, the development of solid electrolytes faces challenges in achieving high ionic conductivity and low interfacial impedance. In this study, we prepared a Ce doped UiO-66(Hf)-base electrolyte using a solvothermal method. The resulting electrolyte exhibited remarkable properties, including high Li-ion conductivity (3.72 × 10−3 S cm−1), a high lithium ion transfer number (tLi+ = 0.66), and stability during stripping electroplating. These impressive results can be attributed to that the shorter length of the Ce-O bond in UiO-66(Hf) compared to the Hf-O bond, which enhances the transformation of Li+ ions. The incorporation of Ce as a dopant into UiO-66(Hf) in solid electrolytes holds great promise for future applications in solid-state batteries.

Sandwich-type composited solid polymer electrolytes to strengthen the interfacial ionic transportation and bulk conductivity for all-solid-state lithium batteries from room temperature to 120 °C

The insurmountable charge transfer impedance at the Li metal/ solid polymer electrolytes (SPEs) interface at room temperature as well as the ascending risk of short circuits at the operating temperature higher than the melting point, dominantly limits their applications in solid-state batteries (SSBs). Although the inorganic filler such as CeO2 nanoparticle content of composite solid polymer electrolytes (CSPEs) can significantly reduce the enormous charge transfer impedance at the Li metal/SPEs interface, we found that the required content of CeO2 nanoparticles in SPEs varies for achieving a decent interfacial charge transfer impedance and the bulk ionic conductivity in CSPEs. In this regard, a sandwich-type composited solid polymer electrolyte with a 10% CeO2 CSPEs interlayer sandwiched between two 50% CeO2 CSPEs thin layers (sandwiched CSPEs) is constructed to simultaneously achieve low charge transfer impedance and superior ionic conductivity at 30 °C. The sandwiched CSPEs allow for stable cycling of Li plating and stripping for 1000 h with 129 mV polarized voltage at 0.1 mA cm−2 and 30 °C. In addition, the LiFePO4/Sandwiched CSPEs /Li cell also exhibits exceptional cycle performance at 30 °C and even elevated 120 °C without short circuits. Constructing multi-layered CSPEs with optimized contents of the inorganic fillers can be an efficient method for developing all solid-state PEO-based batteries with high performance at a wide range of temperatures.

Rationally coordinating polymer enabling effective Li-ion percolation network in composite electrolyte for solid-state Li-metal batteries

The sluggish lithium-ion mobility and inferior electrolyte/electrode interfacial compatibility of composite solid electrolytes greatly hinder the practical application of solid-state lithium-metal batteries. Here, a novel composite polymer electrolyte (CPE) with effective Li+ percolation network is synthesized based on single-ion conductive polymer lithiated polyvinyl formal (LiPVFM) and garnet Li6.4La3Zr2Ga0.2O12 (LLZGO) nanoparticles. The supramolecular interaction between the branched hydroxyl in LiPVFM and the lattice oxygen in LLZGO fillers endows CPE with a continuous percolation structure and improved toughness. Meanwhile, the rational O-Li+ coordination in the LiPVFM random polymer significantly enhances Li+ transfer within the percolation network. Therefore, this as-prepared CPE presents a lithium-ion transference number of 0.75 and an ionic conductivity of 0.527 mS cm−1 at 30 °C, alongside an electrochemical stability window of 4.6 V and a substantial suppression of Li dendrite growth. In addition, ultra-stable interfaces between this CPE and high-voltage LiNi0.6Mn0.2Co0.2O2 (NMC) cathode during cycling can be determined by in-situ electrochemical impedance spectroscopy and in-situ differential electrochemical mass spectrometry characterization. This work is a new exploration for the structural design of CPEs and highlights the importance of “rational coordination” of alkali cation in solid batteries.

Principal component analysis enables the design of deep learning potential precisely capturing LLZO phase transitions

AbstractThe development of accurate and efficient interatomic potentials using machine learning has emerged as an important approach in materials simulations and discovery. However, the systematic construction of diverse, converged training sets remains challenging. We develop a deep learning-based interatomic potential for the Li7La3Zr2O12 (LLZO) system. Our interatomic potential is trained using a diverse dataset obtained from databases and first-principles simulations. We propose using the coverage of the training and test sets as the convergence criteria for the training iterations, where the coverage is calculated by principal component analysis. This results in an accurate LLZO interatomic potential that can describe the structure and dynamical properties of LLZO systems meanwhile greatly reducing computational costs compared to density functional theory calculations. The interatomic potential accurately describes radial distribution functions and thermal expansion coefficient consistent with experiments. It also predicts the tetragonal-to-cubic phase transition behaviors of LLZO systems. Our work provides an efficient training strategy to develop accurate deep-learning interatomic potential for complex solid-state electrolyte materials, providing a promising simulation tool to accelerate solid-state battery design and applications.

A solid-state lithium-ion battery with micron-sized silicon anode operating free from external pressure

Applying high stack pressure (often up to tens of megapascals) to solid-state Li-ion batteries is primarily done to address the issues of internal voids formation and subsequent Li-ion transport blockage within the solid electrode due to volume changes. Whereas, redundant pressurizing devices lower the energy density of batteries and raise the cost. Herein, a mechanical optimization strategy involving elastic electrolyte is proposed for SSBs operating without external pressurizing, but relying solely on the built-in pressure of cells. We combine soft-rigid dual monomer copolymer with deep eutectic mixture to design an elastic solid electrolyte, which exhibits not only high stretchability and deformation recovery capability but also high room-temperature Li-ion conductivity of 2×10−3 S cm−1 and nonflammability. The micron-sized Si anode without additional stack pressure, paired with the elastic electrolyte, exhibits exceptional stability for 300 cycles with 90.8% capacity retention. Furthermore, the solid Li/elastic electrolyte/LiFePO4 battery delivers 143.3 mAh g−1 after 400 cycles. Finally, the micron-sized Si/elastic electrolyte/LiFePO4 full cell operates stably for 100 cycles in the absence of any additional pressure, maintaining a capacity retention rate of 98.3%. This significantly advances the practical applications of solid-state batteries.