Electrolytes For Batteries Research Articles

Lithium-Rich Porous Aromatic Framework Doped Quasi-Solid Polymer Electrolyte for Lithium Battery with High Cycling Stability.

Lithium-ion batteries (LIBs) have revolutionized the energy storage landscape and are the preferred power source for various applications, ranging from portable electronics to electric vehicles. The constant drive and growth in battery research and development aim to enhance their performance, energy density, and safety. Advanced lithium batteries (LIBs) are considered to be the most promising electrochemical storage devices, which can provide high specific energy, volumetric energy density, and power density. However, the trade-off between ionic conductivity and cycling stability is still a major contradiction for SPEs. In this work, a novel hydroxylated PAF-1 was designed and synthesized through post-modification, and the lithium-rich single-ion porous aromatic framework PAF-1-OLi was thereafter prepared by lithiation, achieved with a specific surface area to be 155 m2 g-1 and a lithium content of 2.01 mmol g-1. PAF-1-OLi, lithium bis(trifluoromethanesulfony)limine (LiTFSI), and poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) were compounded to obtain PAF-1-OLi/PVDF by solution casting, which had good mechanical, thermodynamic, and electrochemical properties. The ion conductivity of PAF-1-OLi/PVDF infiltrated with plasticizer was 2.93 × 10-4 S cm-1 at 25 °C. The tLi+ was 0.77, which was much higher than that of the traditional dual-ion polymer electrolytes. The electrochemical window of PAF-1-OLi/PVDF can reach 4.9 V. The Li//PAF-1-OLi/PVDF//LiFePO4 battery initial discharge specific capacity was 147 mAh g-1 and reached 134.9 mAh g-1 after 600 cycles with a capacity retention rate of 91.2%, demonstrating its good cycling stability. The anionic part of lithium salt was fixed on the framework of PAF-1 to increase the Li+ transfer number of PAF-1-OLi/PVDF. The lithium-rich PAF-1-OLi and the LiTFSI provided abundant Li+ sources to transfer, while PAF-1-OLi helped to form a continuous Li+ transport channel, effectively promoting the migration of Li+ in the PAF-1-OLi/PVDF and effectively improving the Li+ conductivity. This study afforded a novel polymer electrolyte based on lithium-rich PAF-1-OLi, which has excellent electrochemical performance, providing a new choice for the polymer electrolyte of lithium batteries.

Numerical investigation of ionic transport and overpotential effects in the electrolyte of the lithium-ion battery

ABSTRACT In this study, we numerically investigated the electrochemical performance of a CGR 17,600 lithium-ion battery (LIB), focusing on lithium-ion transport dynamics within the electrolyte. Using a one-dimensional Nernst-Planck model and finite difference method, we simulated ion diffusion and migration during galvanostatic charge-discharge cycles. Our model predicts concentration profiles, overpotentials, and resistances, identifying a maximum safe operating current of 0.8271 A. The analysis reveals that diffusion dominates during discharge, while migration prevails during charging. The study also characterises ohmic resistance of 0.0497 Ω and steady-state resistance of 0.1904 Ω, underscoring their importance in battery efficiency. Additionally, a transference coefficient of 0.4 highlights effective ion transport, critical for optimising LIB design and performance.

Construction of flexible asymmetric composite polymer electrolytes for high-voltage lithium metal batteries with superior performance

The primary obstacle hindering the application of composite solid electrolytes lies in the varying demands posed by the Li metal anode and the cathode, which needs to be capable of suppressing dendrite growth and resisting high voltage simultaneously. In this work, a new asymmetric composite solid-state electrolyte prepared via electrospinning and in-situ polymerization is proposed to address these shortcomings. In this bilayer architecture, polyacrylonitrile (PAN) layer of high-voltage tolerance, polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) layer of robust mechanical strength and good compatibility towards Li-anode are constructed, and metal-organic-frameworks (MOFs) are pre-embedded within both layers. The unique design provides a wide electrochemical stability window meanwhile ensures uniform lithium deposition. Remarkably, it exhibits a superior lithium utilization of 41 mAh cm−2 using a lean polymer electrolyte precursor and a high critical current density of 2.2 mA cm−2 with a thickness of 40 μm. Beneficial from the formation of a self-adjustable gradient solid electrolyte interphase in the Li/PVDF-HFP interface, the asymmetric electrolyte endows Li||Li and Li||NCM811 cells with excellent cycling stability. Moreover, the solid-state pouch cell exhibits reliable operation under extreme conditions. This work provides inspiration for the design and fabrication of composite solid electrolytes for next-generation high-voltage Li metal batteries.

Stable cycling of halide solid state electrolyte enabled by a dynamic layered solid electrolyte interphase between Li metal and Li3YCl4Br2

Halides are potential electrolytes for Li metal solid state batteries owing to their combination of high ionic conductivity, ductility and electrochemical stability against oxidation. However, their reactivity with the Li metal electrode may result in the formation of secondary compounds hindering their practical utility in terms of cycling performance as key indicator in battery operation. In this work, we investigate the high performance of symmetric cells with Li3YCl4Br2 halide and bare Li-metal electrode, able to withstand 1000 h of Li electrodeposition-dissolution with an overpotential as low as 46 mV. Through a comprehensive analysis employing physico-chemical and electrochemical characterizations, complemented by computational methodologies, we unravel the dynamics of the complex of the Li/halide interface and its evolution during cycling. The reactivity between Li3YCl4Br2 with metallic Li results in the reduction of the halide into LiCl, LiBr and Y metal. Surprisingly, during cycling, those secondary products from the reduction of the halide build a structured solid electrolyte interphase, containing a Y-rich electronic conductive and LiCl and LiBr ionic conductive layers. The particular chemistry and robustness of this solid electrolyte interphase exhibiting a mixed ionic and electronic conductivity appears to be responsible for the outstanding cycling stability.

Strategies for flame-retardant polymer electrolytes for safe lithium-based batteries

Strategies for flame-retardant polymer electrolytes for safe lithium-based batteries

Achieving the Inhibition of Aluminum Corrosion by Dual-Salt Electrolytes for Sodium-Ion Batteries.

Sodium bis(fluorosulfonyl)imide (NaFSI) electrolytes are renowned for their superior physicochemical and electrochemical properties, making them ideal for high-performance sodium-ion batteries (SIBs). However, severe oxidative dissolution of aluminum current collectors (commonly known as Al corrosion) in NaFSI-based electrolytes occurs at high potentials. To address this challenge, aiming to understand the Al corrosion mechanism and develop strategies to inhibit corrosion, we propose dual-salt electrolytes using 0.8 mol L-1 (M) NaFSI and 0.2 M of a second fluorine-containing sodium salt dissolved in EC/PC solutions (1:1, v/v) to construct an insoluble deposits layer on the Al. Dual-salt electrolytes adopting a second sodium salt capable of passivating the Al collector have been extensively investigated through various techniques, such as cyclic voltammetry, scanning electron microscopy, chronoamperometry, X-ray photoelectron spectroscopy, and charge-discharge tests. Our findings demonstrate that introducing sodium difluoro(oxalato)borate (NaDFOB) into the NaFSI electrolytes inhibits Al corrosion, which is attributed to the formation of insoluble deposits of Al-F (AlF3) and B-F containing polymers. Moreover, the capacity retention of Na||Na3V2(PO4)3 (NVP) cells using the NaFSI-NaDFOB dual-salt electrolyte reaches 99.2% along with a Coulombic efficiency over 99.3% at a 1 C rate after 200 cycles. This research provides a practical solution for passivating Al collectors in SIBs with NaFSI electrolytes and promotes the development of sodium batteries with long calendar lifetimes.

In situ bridging soft polymer and robust metal-organic frameworks as electrolyte for long-cycling solid-state potassium-organic batteries

In situ bridging soft polymer and robust metal-organic frameworks as electrolyte for long-cycling solid-state potassium-organic batteries

Iron-vanadium redox flow batteries electrolytes: performance enhancement of aqueous deep eutectic solvent electrolytes via water-tuning

Deep eutectic solvents (DES) are being recognized as a highly promising electrolyte option for redox flow batteries. This study examines the impact of modifying the molar ratio of water to a DES consisting of urea and choline chloride on important measures of electrolyte performance, such as viscosity, cyclic voltammetry, and impedance spectroscopy. According to the findings, when the molar ratio of water to DES is 1:3, the viscosity of the electrolyte falls by 75 %, the peak current density increases by 5–9.5 times, the ionic conductivity increases by 5–10 times, and the ohmic resistance decreases by 60–90 %. This approach greatly enhances the conductivity and diffusion coefficient of the electrolyte, resulting in a novel, cost-effective, and highly efficient electrolyte for iron-vanadium redox flow battery applications. This study enhances the efficiency of DESs at the molecular level, establishing the foundation for future extensive implementations.

Solvation structure and electron isolation synergy of piperidine ionic liquid additives inspires high performance lithium metal batteries

The safety concerns associated with lithium metal stand as the foremost barrier preventing widespread application of lithium metal batteries, especially due to lithium dendrite growth and gas evolution from electrolyte decomposition. This study employed N‑butyl‑N-methyl-piperidinium bis(trifluoro-methyl-sulfonyl) imide (PP14TFSI) as an additive in the electrolyte, aimed at improving the safety attributes of lithium metal batteries. The assessment conducted on the protective mechanism of the PP14TFSI additive unveiled its capability to control create robust and rapidly ion-conductive SEI by adjusting the solvation structure. Simultaneously, PP14+ intercepts free electrons, inhibiting the decomposition of DME and subsequent gas generation. Due to the synergistic effects of these two mechanisms, the rate of gas generation was reduced by half. A comprehensive investigation of lithium metal-based cells exhibited promising performance, maintaining stable cycling for 2160 h at 25 °C, 0.5 mA cm−2, displaying consistently high CE > 98.5 % in a Li||Cu cell. Moreover, at 60 °C, 2 mA cm−2, the cells maintaining stability for 240 cycles while still exhibiting relatively high CE > 98.5 %. In addition, at a low N/P ratio of 4:1, the Li-S battery maintains a high capacity of 673.4 mA h g−1 after 200 cycles, while the Li-LFP battery maintains a capacity of 131.16 mA h g−1 and capacity retention of 91.02 % after 300 cycles at 1 C. This research lays groundwork for the exploration of ionic liquids as additives in lithium metal battery electrolytes to further enhance battery safety performance.

Reconstructing Helmholtz Plane Enables Robust F-Rich Interface for Long-Life and High-Safe Sodium-Ion Batteries.

Hard carbon (HC) is the most commonly used anode material in sodium-ion batteries. However, the solid-electrolyte-interface (SEI) layer formed in carbonate ester-based electrolytes has an imperceptible dissolution tendency and a sluggish Na+ diffusion kinetics, resulting in an unsatisfactory performance of HC anode. Given that electrode/electrolyte interface property is highly dependent on the configuration of Helmholtz plane, we filtrated proper solvents by PFBE (PF6 - anion binding energy) and CAE (carbon absorption energy) and disclosed the function of chosen TFEP to reconstruct the Helmholtz plane and regulate the SEI film on HC anode. Benefiting from the preferential adsorption tendency on HC surface and strong anion-dragging interaction of TFEP, a robust and thin anion-derived F-rich SEI film is established, which greatly enhances the mechanical stability and the Na+ ion diffusion kinetics of the electrode/electrolyte interface. The rationally designed TFEP-based electrolyte endows Na||HC half-cell and 2.8 Ah HC||Na4Fe3(PO4)2P2O7 pouch cell with excellent rate capability, long cycle life, high safety and low-temperature adaptability. It is believed that this insightful recognition of tuning interface properties will pave a new avenue in the design of compatible electrolyte for low-cost, long-life, and high-safe sodium-ion batteries.

Polar groups promoting in-situ polymerization phase separation for solid electrolytes enabling solid-state lithium batteries

Plastic-crystal-embedded elastomer electrolytes (PCEEs), produced through polymerization-induced phase separation (PIPS), are gaining popularity as solid polymer electrolytes (SPEs). However, it remains to be investigated whether all monomer molecules can achieve polymerization-induced phase separation and the corresponding differences in lithium metal battery performance. Herein, we prepared PCEEs with different functional groups (OH, CN, F) through in situ polymerization. Research findings show that PCEE containing – CN or – F achieves the separation of the plastic crystalline phase and succinonitrile (SN) phase, whereas PCEE containing OH cannot due to hydrogen bonding with the SN phase. Notably, the PCEE synthesized with the F monomer (FBA-PCEE) exhibited exceptional interfacial stability with lithium metal anodes and lithium iron phosphate (LFP) cathodes, due to its unique coordination mechanism with lithium ions. The FBA-PCEE demonstrated a high ionic conductivity (2.02 × 10−3 S cm−1) and lithium-ion migration number (tLi+ = 0.75). Moreover, lithium symmetric cells incorporating FBA-PCEE demonstrated stable cycling performance for more than 1000 h at a current density of 0.1 mA cm−2, resulting in the development of a solid electrolyte interphase (SEI) rich in LiF, Li3N, and Li2CO3 over time. Additionally, incorporating FBA-PCEE facilitated the stable cycling of LPF over 1000 cycles at 0.5C, maintaining a capacity retention of 77.38 % after 500 cycles. When coupled with high-voltage Nickel Cobalt Manganese Oxide (NCM-622) cathodes and lithium metal anodes, a discharge capacity of 119.70 mAh g−1 at 0.1C was sustained after 100 cycles, exhibiting a capacity retention of 78.95 %. This study elucidates the critical role of monomer design in achieving PIPS, offering valuable insights into developing high-performance polymer composite electrolytes for advanced lithium metal batteries.

Investigating the safety of solid/liquid hybrid electrolyte lithium-ion battery: A comparative study with traditional LIBs under abuse condition

Lithium-ion battery (LIB) with solid‒liquid hybrid electrolyte is an important milestone in the development of all-solid-state battery (ASSB) to achieve higher energy density. In-depth understanding of the safety of solid‒liquid hybrid electrolyte battery (HS-LIB) is investigated for the first time: a detailed analysis and comparison of the possibility and severity of thermal runaway (TR) of HS-LIB and LIB are performed under typical abuse conditions to further explain the practical safety of HS-LIB in multiple dimensions. Poor thermal safety is identified by the lower self-heating onset temperature Tonset (78 °C) and thermal runaway triggering temperature Ttr (138 °C) of HS-LIB with 100 % state of charge (SOC), as well as higher maximum temperature Tmax (>1200 °C) and 2–3 times maximum temperature rise rate dT/dtmax (349.3 °C/s) higher than LIBs. The significant volume changes of SiOx as an anode material contribute to uneven SEI formation, while the resultant cracks and voids accelerate SEI decomposition prematurely. The lower thermodynamic parameter-apparent activation energy Ea also indicates that the test battery has lower thermal stability, and the comparative results of the TNT-equivalent corroborated the greater thermal hazards. External overheating conditions also results in a lower Ttr (168 °C) and shorter time to thermal runaway ttr (177 s) due to faster heat absorption with dT/dtmax (933.8 °C/s). Self-generation of heat by SE in the temperature range that triggers the main response to TR and the high energy release in a short period of time exacerbate the TR hazard. Worse electrical behavior is proven through lower state of charge (114 %) and higher dT/dtmax (>420 °C/s). Encouragingly, HS-LIB exhibits excellent mechanical safety, due to the double roles of solid-state electrolytes: as an electrolyte and a separator, which avoids internal short-circuits caused by melting of the separator at hot spots. Lower thermal stability with greater hazards is explained by a correlation mechanism analysis and these experimental results can provide some reference for the safe design of ASSB.

Freeze-Vulnerable Plastic Crystal to Cryogenic Liquid Electrolyte for Lithium Batteries by Deep Freezing-Point Depression.

Low-Tf solvents (Tf = freezing point) are considered and employed for low-temperature lithium-ion battery (LIB) electrolytes to keep electrolytes in the liquid phase at low temperatures. Unfortunately, Tf is synchronized with Tb (boiling point) so low Tf brings Tb down and therefore discourages the thermal stability of electrolytes using low-Tf solvents. In this work, 1) the hot wing of LIB-working temperature by employing a high-Tb (inevitably high-Tf) solvent and 2) the cold wing by using a significant Tf depression is secured. Sulfolane is employed as the high-Tf (therefore, high-Tb) and high-Kf (Kf = cryoscopic constant) solvent since its mesomorphic state between solid and liquid. That abnormally and significantly decreases the enthalpy of fusion, and resultantly grants extremely high Kf at 66.4Km-1. By employing sulfolane with 2m lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), the liquid-phase temperature window down to <-80°C for the cold wing and simultaneously guaranteed its flash point at >+150°C for the hot wing is successfully extended. LIB cells with lithium iron phosphate and lithium metal worked in a good stand with 2m LiTFSI/sulfolane at room temperature, -30°C as an ambient cold, -74°C as a deep cold, and +80°C as a deep hot.

Soy protein as a dual-functional bridge enabling high performance solid electrolyte for Li metal batteries

A high-performance solid electrolyte is critical for all-solid-state Li metal batteries which possess good safety and high energy densities. In this study, inspired by the unique ionic transport function and excellent adhesive properties of natural proteins, we successfully generated a novel solid electrolyte by applying soy protein as a dual-functional bridge to enable additional ion-conduction pathways and improve mechanical performance. The solid electrolyte with soy protein that interacts with both SiO2 nanofabrics and polypolyethylene oxide (PEO) exhibits high ionic conductivity of 10−5 S cm−1 (vs. 10−6 S cm−1 of SiO2/PEO), improved Li+ transference number of 0.550 (vs. 0.446 of SiO2/PEO), high Young's modulus of 1.862 MPa (vs. 0.356 MPa of SiO2/PEO) and excellent flexibility. As a result, the solid-state batteries with LiFePO4 as cathode demonstrate a stable discharge capacity. This work provides a new strategy to advance the performance of solid electrolytes for achieving long-lifespan all-solid-state batteries.

Real-time monitoring the formation of polymer double network for gel polymer electrolyte by means of dielectric spectroscopy

A non-destructive method of detecting the internal information of the system is attempted in a polymer double network for gel polymer electrolyte in lithium-ion battery. The real-time monitoring for polymerization of 1,3-dioxolane (DOL) and cross-linking of cyanoethyl poly(vinyl alcohol) (PVA-CN) is carried out in a coin cell at 0–80 ℃ by means of dielectric spectrum. A widely distributed dielectric relaxation varying with monitoring time and temperature is observed in the frequency range of 3–103 kHz, and the relaxation parameters of the three sub-relaxations are obtained by fitting the dielectric spectrum with the HN equation. It is found that the relaxation intensity Δε and relaxation time τ are obviously dependent on the monitoring time and temperature: Δε and τ change obviously near the respective gel points of DOL and PVA-CN (DOL at 25 ℃, PVA-CN at 60 ℃), suggesting gelation at two gel points respectively. The different structural changes of the system before and after gelling temperature are speculated, and the possible microstructure of the system in each temperature range is proposed after analyzing the relaxation parameters. The applicability of the real-time dielectric monitoring in the study of the structure of gel polymer electrolytes is preliminarily concluded.

Quasi-Gel Polymer Electrolyte Interfaced with Electrodes through Solvent-Swollen Poly(ethylene oxide) for High-Performance Lithium/Lithium-Ion Batteries.

Solid polymer electrolytes (SPEs) are regarded as a superior alternative to traditional liquid electrolytes of lithium-ion batteries (LIBs) due to their improved safety features. The practical implementation of SPEs faces challenges, such as low ionic conductivity at room temperature (RT) and inadequate interfacial contact, leading to high interfacial resistance across the electrode and electrolyte interfaces. In this study, we addressed these issues by designing a quasi-gel polymer electrolyte (QGPE), a blend of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(ethylene oxide) (PEO), and succinonitrile (SN), with the desired mechanical strength, ionic conductivity, and interfacial stability through a simple solution casting technique. The QGPE features a thin solvated PEO layer on its surface, which wets the electrode, reducing the interfacial resistance and ensuring a homogeneous Li-ion flux across the interface. The optimized QGPE exhibits a good lithium-ion conductivity of 1.14 × 10-3 S cm-1 with a superior lithium-ion transference number of 0.7 at 25 °C. The Li/QGPE/Li symmetric cell exhibits a highly reversible lithium plating/stripping process for over 1300 h with minimal voltage polarization of ∼20 mV. The Li/QGPE/LiFePO4 full cell demonstrates good rate capability and excellent long-term cycling performance at a 0.1 C rate at 25 °C, maintaining a specific discharge capacity of 148 mAh g-1 over 200 cycles. The effectiveness of QGPE for LIBs is proven using a graphite/QGPE/LiFePO4 4 × 4 cm pouch cell, showcasing outstanding flexibility and tolerance against intentional abuse.

Aloe Vera‐Based Green and Sustainable Electrolyte for Zinc Ion Batteries

AbstractAqueous zinc‐ion batteries (ZIBs) present significant promises for next‐generation energy storage systems. However, challenges such as the zinc (Zn) dendrite formation and parasitic side reactions during Zn plating‐stripping hinder their development. Herein, an aloe vera (AV)‐based green and sustainable electrolyte is formulated to increase the electrochemical stability of the ZIBs, reducing the free water molecules, and decreasing the hydrogen evolution reaction (HER) and Zn dendrite formation. The obtained results confirm that the AV‐based electrolyte enhances the electrochemical stability and boosts the performance of the ZIBs. The formulated AV‐based electrolyte in symmetrical Zn//Zn cells demonstrates an outstanding cycle life of 4500 h, significantly longer than the aqueous electrolytes for ZIBs. The quinone moiety of the AV‐based electrolytes provides higher specific capacities for VO2(D) and activated carbon cathodes in full devices. AV‐based green electrolytes allow the realization of sustainable and safe energy storage systems for next‐generation applications.

Mixed conductive layer formed by ZnO–graphite conversion–reaction enables dendrite–free all–solid–state lithium metal batteries

Largescale application of sulfide solid electrolytes (SSEs) in nextgeneration allsolidstate Limetal batteries is currently limited by an unstable Li/SSEs interface and fast Lidendrite formation/growth during charging. This work has addressed these challenges by introducing ZnO and graphite composite to the surface of lithium metal, creating a multifunctional conductive composite layer with Ligraphite and LiZn alloy. This interfacial layer enhances Liion transport and minimizes side reactions at the Li/SSEs interface. As a result, the interfacial resistance of Li/SSEs decreased from 14.2 to 11.7 Ω cm², and the critical current density (CCD) significantly improved from 0.8 to 2.7 mA cm2. Moreover, the protective layer enables stable cycling of both Li/Li symmetric and LiNi0.8Mn0.1Co0.1O2/Li cells even at high current densities.

Exploring the capabilities and limitations of the Van Hove function to understand directional correlations in ion movements within Li-ion battery electrolytes.

Understanding microscopic directional correlations in ion movements within lithium-ion battery (LIB) electrolytes is important because these correlations directly affect the ionic conductivity. Onsager transport coefficients are widely used to understand these correlations. On the other hand, the Van Hove function (VHF) is also capable of determining correlated motions. However, identifying various types of ion correlated motions in LIB electrolytes using VHF is not well explored. Here, we have conducted molecular dynamics simulations of a representative experimental LIB electrolyte system-lithium hexafluorophosphate (LiPF6)-at different concentrations in a (9:1 wt. %) mixture of ethyl methyl carbonate and fluoroethylene carbonate in order to explore the capabilities and limitations of using VHF to understand different types of ion correlations. We conclude that analysis of VHF can qualitatively describe both the positive correlation between cation-anion at different salt concentrations and the negative correlation between cation-cation and anion-anion present in high salt concentration, but it cannot foretell which correlation is dominating at any given electrolyte concentration. This type of quantitative information can be obtained only via Onsager's approach. This could be seen as a limitation of relying solely on VHF to fully understand ion correlation in electrolyte media.

Phosphonitrile based porous organic polymers as effective flame-retardant electrolytes for lithium battery

Developing electrolytes with flame-retardant properties become the critical factor in making high safety lithium batteries. As phosphonitrile-based compounds are a kind of typical flame-retardant materials, herein, taking phosphonitrile-based aldehyde as the basic organic building blocks, two porous organic polymers (POPs) named as PVPH and PVPH-CO2H were successfully fabricated after solvothermal reaction with 1,3-diaminobenzene (MPD) and 5-carboxy-1,3-diaminobenzene (MPD-CO2H), respectively for electrolytes of lithium batteries. Studies revealed that both of the phosphonitrile-based POPs demonstrate good thermal stability and excellent flame-retardant properties, suggesting they are promising flame-retardant electrolytes for the application in battery. Battery performance investigations revealed that both of them, especially PVPH-CO2H, show good performance after assembling them into lithium batteries. This study paves the way to improve battery safety performance by employing the flame-retardant phosphonitrile-based porous polymers as effective electrolytes. Moreover, it also broadens the application of flame-retardant materials in energy storage materials.