LiFePO4 Cells Research Articles

ZnO Quantum Dots as PEO-Based Solid Electrolytes Fillers for Lithium Metal Batteries.

PEO-based solid polymer electrolyte (PEO SPE) is regarded as one of the most promising solid electrolytes due to its exceptional flexibility, cost-effectiveness, and ease of integration. However, its commercialization is hindered by inadequate ionic conductivity and unstable interface. By incorporating proper ZnO quantum-dots (QDs) fillers with enhanced surface activity, the ion transport inner the PEO-based electrolyte can be improved along with enhanced REDOX kinetics at the Li/PEO interface. The ionic conductivity reaches 5.97×10-4 S cm-1 at 60 °C. Moreover, ZnO QDs exhibit a quantum size effect and possess lithiophilic characteristics that promote uniform nucleation and redeposition of Li+ while forming a stable Li-Zn alloy. This inhibits lithium dendrite formation and enhances the stability of Li anode. Li//Li cell with 3 % ZnO QDs works steadily for more than 2100 h at 60 °C with 0.1 mA cm-2. The assembled Li//LiFePO4 cell provides a reversible capacity of 134.91 mAh g-1 after200 cycles at 0.1 C.

Experimental study on the internal pressure evolution of large-format LiFePO4 battery during thermal runaway

The safety problems of lithium-ion batteries, such as fire and explosion, have become the main issues constraining the rapid development of electrochemical energy storage. This paper proposes a new method to obtain the internal pressure and gas components of battery under adiabatic condition. Subsequently, the internal pressure evolution of a fully charged 300 Ah LiFePO4 (LFP) cell during thermal runaway (TR) are analyzed. At the temperature of safety venting (SV), the internal peak pressure recorded is 412 kPa and the gas release of H2 and CO are 35.2 % and 23.7 %, respectively. Basing on the analysis, the gas release temperature calculated by internal pressure is about 5 K lower than self-generated heat temperature. Before SV, the electrolyte volatilization and gas releasing are decoupled, and the gas release is about 0.009 mol. The internal pressure evolution of battery can be divided into three stages. At stage C, the gas release which cause SV account for 43.97 % of the gas volume and the reactions releasing H2 and CO gas are the prime chemical reason for SV. These results are of great significance to the setting of early warning system and the emergency response to TR.

A near-single-ion conducting polymer-in-ceramic electrolyte for solid-state lithium metal batteries with superior cycle stability and rate capability

Composite solid-state electrolytes (CSE) represent a promising alternative to conventional porous separators and organic liquid electrolyte systems in commercialized lithium metal battery (LMBs), offering effective dendrite suppression, high interfacial compatibility and enhanced cycle life. This study introduces a polymer-in-ceramic electrolyte, which is synthesized by blending perovskite-type inorganic electrolyte Li1.5La1.5TeO6 (LLTeO) with polymethyl methacrylate (PMMA) and polyvinylidene fluoride (PVDF), denoted as PMMA/PVDF-LLTeO. The resulting CSE features a dense, non-porous structure, high mechanical strength, excellent thermal stability, and a broad electrochemical window. Notably, with the incorporation of a high ceramic filler content (up to 70 %), the CSE promotes a hybrid ion transport mechanism, yielding a near-single-ion conducting behavior with an ion transference number of 0.833, and a high elastic modulus of approximately 1 GPa. These attributes collectively contribute to the suppression of dendrite growth, as analyzed through multiphysics-based simulations. Li//Li symmetric cells using PMMA/PVDF-LLTeO-70 exhibit robust lithium stripping-plating stability, with a critical current density of 0.45 mA cm−2. Furthermore, the corresponding Li//LiFePO4 cells exhibit superior rate performance and cyclic stability, achieving over 150 cycles with a capacity retention rate of 92.2 % at high temperatures (60 °C). This research highlights the potential of the proposed CSE with high-temperature applications, significantly improving the safety and performance of LMBs

Scalable Production of Thin and Durable Practical Li Metal Anode for High‐Energy‐Density Batteries

AbstractUtilization of thin Li metal is the ultimate pathway to achieving practical high‐energy‐density Li metal batteries (LMBs), but its practical implementation has been significantly impeded by formidable challenges of poor thinning processability, severe interphase instability and notorious dendritic Li growth. Here we report a practical thin (10–40 μm) Li/Mo/Li2Se with concurrently modulated interphase and mechanical properties, achieved via a scalable mechanical rolling process. The in situ generated Li2Se and Mo not only enhance the mechanical strength enabling the scalable fabrication of thin Li metal, but also promote homogeneous Li electrodeposition. Significantly, the Li/Mo/Li2Se demonstrates ultrahigh‐rate performance (15 mA cm−2) and ultralong‐lifespan cycling sustainability (2700 cycles) with exceptional anti‐pulverization capability. The Li|LiFePO4 cells show substantially prolonged cyclability over 1200 cycles with an ultralow decay rate of ~0.01 % per cycle. Moreover, the Li|LiNi0.8Co0.1Mn0.1O2 pouch cells deliver enhanced cycling stability even under the extremely harsh conditions of low negative‐to‐positive‐capacity (N/P) ratio of ~1.2 and lean electrolyte of ~0.95 g Ah−1, showing an exceptional energy density of 329.2 Wh kg−1. This work sheds light on facile pathway for scalable production of durable thin Li metal anode toward reliable practicability.

Super SEI-Forming Anion for Enhanced Interfacial Stability in Solid-State Lithium Metal Batteries.

The extremely high chemical reactivity of lithium metal (Li°) electrodes and its enormous volume change during repetitive cycles cause continuous interfacial degradations in prevailing organic electrolytes, thus deteriorating the cycling performances of rechargeable lithium metal batteries (LMBs). Herein, departing from traditional wisdom on the design of electrolyte components, a super SEI-forming anion (SSA), as an efficient percussor for building stable interphases on Li° electrode, is proposed. Comprehensive investigations related to the unique anion chemistry of SSA reveal that the sulfonate and polyfluoroalkyl functionalities synergistically contribute to uniform spatial distributions of designer interfacial species, greatly improving the surface coverage property and conformal ability of the resulting interphases. Consequently, the incorporation of SSA leads to significant improvements in the cyclability of Li° electrode (exceeding 575 mAh cm-2 before failure) and the corresponding rechargeable Li°||LiFePO4 cells [a five-time increase in lifespan as compared to the benchmark cell with the popular SEI-forming anion bis(fluorosulfonyl)imide (FSI)]. The present work offers a paradigm shift to tame the notorious interfacial issues via upgraded anion chemistry, which can promote the practical development of rechargeable LMBs and other kinds of metal batteries.

Analysis of the inhibition effects of C6F12O and low-pressure carbon dioxide on 72 Ah LiFePO4 module under the overcharging abuse condition

Fire disasters that happened in the energy storage station of LiFePO4 (LFP) cells have been growing rapidly in recent years. To meet the urgent need for fire and explosion prevention caused by the abused LFP cells, the application of C6F12O and low-pressure carbon dioxide (LCD) is proposed. The inhibition effects are investigated quasi-quantitatively. While the average mass flow rate of LCD is 4 times higher than that of C6F12O, the economy of LCD far exceeds C6F12O (the quality unit price of C6F12O is about 10 times to LCD). In particular, the suppression time of LCD is 9 times shorter than C6F12O when they were all released at the side of the module box alone. LCD shows extraordinary module cooling ability on the overcharged LFP module. The pure C6F12O application makes it hard to prevent thermal runaway over long durations. The releasing position of C6F12O (directly above the safety valve and on the side of the LFP module) is also tested. It is easier to suppress the flame when C6F12O is released directly above the safety valve. Additionally, the re-ignition is observed due to the electrostatic spark generated by the charging wire during the suppression process.

Operando Stack Pressure Measurement of LFP/Graphite and LMFP/Graphite Cells to aid in State of Charge Prediction

Abstract One of the biggest issues facing electric vehicles with LiFePO4 (LFP) batteries is state of charge management. Over much of the state of charge window, the voltage of both LFP and LiMnxFe1-xPO4 (LMFP) batteries does not vary. Therefore, state of charge management for LFP batteries relies on coulomb counting, which requires frequent charging to 100% to remain accurate. We propose to use the signal from pressure sensors placed between prismatic cells in battery modules to help determine the state of charge of LFP and LMFP batteries. Using LFP and LMFP pouch cells to demonstrate this principle, the pressure vs. time profiles of cells constrained in fixed volumes reveal distinct and repeatable profiles, which can be used to determine the state of charge in combination with voltage monitoring. Additionally, a simulated LFP battery pack was constructed and the pressure vs. time profile was monitored in the presence of compliant material under low initial force loadings to demonstrate how this could work in an EV battery.

Degradation mechanism and assessment for different cathode based commercial pouch cells under different pressure boundary conditions

Lithium-ion pouch cell exhibits expansion behavior during cycling, which determines the overall performance and external pressure evolution. It is significant to reveal the impact of pressure boundary conditions on battery degradation. This study investigated the degradation mechanism of different cathode-based pouch cells (LiFePO4 (LFP) and Li(Ni0.6Co0.2Mn0.2)O2 (NCM622)) under four distinct pressure boundary conditions (I-II. clamping with two foam pads having varying compression force deflection (CFD) respectively, III. without foam pad, IV. unpressurized). One hundred of pre-experiment cycles determined the optimal external pressure (12.5 kPa) to slow down the degradation process. Subsequently, multi-cell paralleled cycling experiments were conducted for 1000 cycles. The capacity degradation of LFP and NCM cells with the optimal condition was 6.0 % and 12.6 % less than that of unpressurized cells. The electrochemical tests indicated that unpressurized cells had the fastest rate of lithium-ion loss, which is related to solid electrolyte interface (SEI) film growth and lithium plating. Post-mortem characterization analysis further revealed that the pressure boundary condition is crucial for the electrode morphology, pressure distribution, and gas generation, which affect battery degradation. The pressurized cells’ surface exhibited fewer instances of lithium plating. With the stiff foam clamped, pouch cell swelling can be absorbed while maintaining contact between cell components, resulting in fewer electrode folds and cracks. This study provides valuable insights for designing long-lifespan battery modules or packs.

Bimetal Fluorides with Adjustable Vacancy Concentration Reinforcing Ion Transport in Poly(ethylene oxide) Electrolyte.

The poor ambient ionic transport properties of poly(ethylene oxide) (PEO)-based SPEs can be greatly improved through filler introduction. Metal fluorides are effective in promoting the dissociation of lithium salts via the establishment of the Li-F bond. However, too strong Li-F interaction would impair the fast migration of lithium ions. Herein, magnesium aluminum fluoride (MAF) fillers are developed. Experimental and simulation results reveal that the Li-F bond strength could be readily altered by changing fluorine vacancy (VF) concentration in the MAF, and lithium salt anions can also be well immobilized, which realizes a balance between the dissociation degree of lithium salts and fast transport of lithium ions. Consequently, the Li symmetric cells cycle stably for more than 1400 h at 0.1 mA cm-2 with a LiF/Li3N-rich solid electrolyte interphase (SEI). The SPE exhibits a high ionic conductivity (0.5 mS cm-1) and large lithium-ion transference number (0.4), as well as high mechanical strength owing to the hydrogen bonding between MAF and PEO. The corresponding Li//LiFePO4 cells deliver a high discharge capacity of 160.1 mAh g-1 at 1 C and excellent cycling stability with 100.2 mAh g-1 retaining after 1000 cycles. The as-assembled pouch cells show excellent electrochemical stability even at rigorous conditions, demonstrating high safety and practicability.

Rational design of the temperature-responsive nonflammable electrolyte for safe lithium-ion batteries

The development of nonflammable electrolytes is critical for breaking the trade-off between the safety and energy density in Li-ion batteries (LIBs). Here, a rational design strategy of temperature-responsive nonflammable electrolytes (TRNEs) is proposed which are capable to prevent the heat accumulation and extinguish the fire efficiently during thermal runaway. Compared to the conventional phosphate- or halogen-based flame retardants, the TRNE based on low-cost and multifunctional methylurea (MU) was demonstrated with the lowest volatility (11.6 % weight loss) below 250 °C, and the highest efficacy to extinguish the fire at >210.4 °C through heat absorption, inert gases generation and char layer formation. In addition, the developed MU-based TRNEs enable higher stability and rate capability of LIBs compared to various nonflammable electrolytes. A Li||LiFePO4 (LFP) cell employing MU-based TRNE achieved higher stability (94.9 % capacity retention for 1500 cycles) than commercial electrolyte. A Ni-rich Li||LiNi0.8Mn0.1Co0.1O2 (NMC811) system was demonstrated with superior rate capability and high stability for 700 cycles (2.72 months) with the capacity retention of 89.9 %. Combining low cost and volatility, as well as high stability, rate capability and fire extinguishing efficacy, we demonstrate a promising design strategy to improve the battery safety for high-energy-density LIBs.

Li2ZnCu3 modified Cu current collector to regulate Li deposition

Rationally designing a current collector that can maintain low lithium (Li) porosity and smooth morphology while enduring high‐loading Li deposition is crucial for realizing the high energy density of Li metal batteries, but it is still challengeable. Herein, a Li2ZnCu3 alloy‐modified Cu foil is reported as a stable current collector to fulfill the stable high‐loading Li deposition. Benefiting from the in‐situ alloying, the generated numerous Li2ZnCu3@Cu heterojunctions induce a homogeneous Li nucleation and dense growth even at an ultrahigh capacity of 12 mAh cm‐2. Such a spatial structure endows the overall Li2ZnCu3@Cu electrode with the manipulated steric hindrance and outmost surface electric potential to suppress the side reactions during Li stripping and plating. The resultant Li||Li2ZnCu3@Cu asymmetric cell preserves an ultrahigh average Coulombic efficiency of 99.2% at 3 mA cm‐2/6 mAh cm‐2 over 200 cycles. Moreover, the Li‐Li2ZnCu3@Cu||LiFePO4 cell maintains a cycling stability of 87.5% after 300 cycles. After coupling with the LiCoO2 cathode (4 mAh cm‐2), the cell exhibits a high energy density of 407.4 Wh kg‐1 with remarkable cycling reversibility at an N/P ratio of 3. All these findings present a doable way to realize the high‐capacity, dendrite‐free, and dense Li deposition for high‐performance Li metal batteries.

Li2ZnCu3 Modified Cu Current Collector to Regulate Li Deposition.

Rationally designing a current collector that can maintain low lithium (Li) porosity and smooth morphology while enduring high-loading Li deposition is crucial for realizing the high energy density of Li metal batteries, but it is still challengeable. Herein, a Li2ZnCu3 alloy-modified Cu foil is reported as a stable current collector to fulfill the stable high-loading Li deposition. Benefiting from the in situ alloying, the generated numerous Li2ZnCu3@Cu heterojunctions induce a homogeneous Li nucleation and dense growth even at an ultrahigh capacity of 12 mAh cm-2. Such a spatial structure endows the overall Li2ZnCu3@Cu electrode with the manipulated steric hindrance and outmost surface electric potential to suppress the side reactions during Li stripping and plating. The resultant Li||Li2ZnCu3@Cu asymmetric cell preserves an ultrahigh average Coulombic efficiency of 99.2 % at 3 mA cm-2/6 mAh cm-2 over 200 cycles. Moreover, the Li-Li2ZnCu3@Cu||LiFePO4 cell maintains a cycling stability of 87.5 % after 300 cycles. After coupling with the LiCoO2 cathode (4 mAh cm-2), the cell exhibits a high energy density of 407.4 Wh kg-1 with remarkable cycling reversibility at an N/P ratio of 3. All these findings present a doable way to realize the high-capacity, dendrite-free, and dense Li deposition for high-performance Li metal batteries.

Boron Surface Treatment of Li7La3Zr2O12 Enabling Solid Composite Electrolytes for Li-Metal Battery Applications.

Despite being promoted as a superior Li-ion conductor, lithium lanthanum zirconium oxide (LLZO) still suffers from a number of shortcomings when employed as an active ceramic filler in composite polymer-ceramic solid electrolytes for rechargeable all-solid-state lithium metal batteries. One of the main limitations is the detrimental presence of Li2CO3 on the surface of LLZO particles, restricting Li-ion transport at the polymer-ceramic interfaces. In this work, a facile way to improve this interface is presented, by purposely engineering the LLZO particle surfaces for a better compatibility with a PEO:LiTFSI solid polymer electrolyte matrix. It is shown that a surface treatment based on immersing LLZO particles in a boric acid solution can improve the LLZO surface chemistry, resulting in an enhancement in the ionic conductivity and cation transference number of the CPE with 20 wt % of boron-treated LLZO particles compared to the analogous CPE with non-treated LLZO. Ultimately, an improved cycling performance and stability in Li//LiFePO4 cells was also demonstrated for the modified material.

Fluorine-Rich Electrolyte Additive for Achieving Dendrite-Free Lithium Anodes at Low Temperatures.

The practical application of lithium metal anodes is significantly impeded by poor interfacial stability and uncontrolled dendrite growth. Herein, we introduce methyl trifluoroacetate (MTFA), a low-melting-point small molecule, as an electrolyte additive in an ether-based electrolyte. This additive facilitates the formation of an in situ composite solid electrolyte interphase (SEI) layer that is rich in LiF and features an ester-based flexible matrix. The resulting composite layer exhibits high ionic conductivity and mechanical stability, effectively regulating the lithium deposition behavior over a broad temperature range and inhibiting dendrite formation. Based on MTFA, the Li||Li symmetrical cell achieves a lifespan exceeding 5000 h at room temperature and 800 h at -20 °C, both with ultralow overpotential and exceptional cycling stability. In Li||LiFePO4 full cells with a high-area loading (10.52 mg cm-2) and an N/P ratio of 1.68, an average capacity decay of merely 0.096% per cycle is observed over 200 cycles. Even at -20 °C, the Li||LiFePO4 cell shows a CE of over 99% and maintains stable cycling performance. This work provides an innovative approach for optimizing lithium metal anode interfaces and enhancing low-temperature operation capabilities through the use of electrolyte additives.

Anions‐Trappable Hollow Mesoporous Nanoparticle Coating Enables High‐Performance and Safe Lithium Metal Batteries

AbstractPolyolefin separators, such as polypropylene (PP) and polyethylene (PE) separators, are the commonly used separators for lithium batteries, which have good mechanical properties and chemical/electrochemical stability, but their high‐temperature dimensional stability is poor and Li+ transference number (t Li+) is low. Recently, much attention has been paid to developing separators with new substrates, but so far there is no separator to replace the polyolefin separator for large‐scale application. Therefore, the surface modification of the polyolefin separator to enhance its functionality is a simple and effective method. Among many modified layers, the porous modified layer can store the electrolyte and provide enough space for ion transport. In this work, a hollow mesoporous silica nanosphere (mSiO2) is prepared for the PP separator multifunctional coating to improve the electrochemical performance and high‐temperature safety of the PP separator. The experimental and theoretical results show that the mSiO2 coating can not only improve the electrolyte wettability and high‐temperature dimensional stability of the PP separator, but also promote the Li+ transport, so that the mSiO2/PP separator exhibits high ionic conductivity (2.35 mS cm−1) and high t Li+ (0.63). As a result, Li//LiFePO4 cells using mSiO2/PP separators exhibit excellent cycling performance, rate performance, and high‐temperature safety.

In Situ Inorganic/Organic Protective Layer on Carbon Paper as Advanced Current Collector for Robust Li Metal Anode.

Lithium (Li) metal is regarded as the most promising anode for next-generation batteries with high energy density. However, the uncontrolled dendrite growth and infinite volume expansion during cycling seriously hinder the application of Li metal batteries (LMBs). Herein, an inorganic/organic protective layer (labeled as BPH), composed of in situ formed inorganic constituents and PVDF-HFP, is designed on the 3D carbon paper (CP) surface by hot-dipping method. The BPH layer can effectively improve the mechanical strength and ionic conductivity of the SEI layer, which is beneficial to expedite the Li-ion transfer of the entire framework and achieve stable Li plating/stripping behavior. As a result, the modified 3D CP (BPH-CP) exhibits an ultrahigh average Coulombic efficiency (CE) of ≈99.7% over 400 cycles. Further, the Li||LiFePO4 (LFP) cell exhibits an extremely long-term cycle life of over 3000 cycles at 5 C. Importantly, the full cell with high mass loading LiFePO4 (20mgcm-2) or LiNi0.8Co0.1Mn0.1O2 (NCM, 16mgcm-2) cathode exhibits stable cycling for 100 or 150 cycles at 0.5 C with high-capacity retention of 86.5% or 82.0% even at extremely low N/P ratio of 0.88 or 0.94. believe that this work enlightens a simple and effective strategy for the application of high-energy-density and high-rate-C LMBs.

PEO kaolinite intercalation interface accelerates lithium-ion transfer for all-solid-state lithium metal batteries

The improvement of ionic conductivity and Li dendrite inhibition capability of poly(ethylene oxide)(PEO)-based solid polymer electrolytes(SPEs) is urgent for the development of all-solid-state lithium metal batteries (ASSLMBs). Here, intercalated composite consisted with PEO polymer chains inserted into the clay gallery of the formamide intercalated kaolinite (KM) is formed. Due to this alternating organic-inorganic layered structure, the crystallinity of PEO decreases to 26.2% and the ion conductivity of SPE with 3% KM of PEO mass added(PEO+KM-3) increased to 1.43 × 10−3 S cm−1 at 60 °C. Besides, bis (trifluoromethane) sulfonimide lithium salt (LiTFSI) interacts with formamide to form a complex, making the local solvated Li+ transports close to a quasi-solid model. PEO+KM-3 SPE exhibits a good inhibition effect on lithium dendrites due to the formation of organic silicon at lithium anode side, and Li/ PEO+KM-3/Li cell works steadily for more than 1600 h at 60 °C with 0.1 mA cm−2. The assembled Li//LiFePO4 cell provides a capacity of 118 mAh g−1 after 500 cycles at 0.5 C at 60 °C.

Mechanical methods for materials concentration of lithium iron phosphate (LFP) cells and product potential evaluation for recycling.

The production and sales of lithium-ion batteries (LIB) are rapidly expanding nowadays, causing a significant impact on the consumption of critical raw materials, such as lithium. Thus, developing and improving methods for the separation and recovery of materials from LIBs is necessary to ensure the supply of critical raw materials, as well as to meet the recycling targets set by some countries. This study evaluated and compared two mechanical routes to concentrate materials of LiFePO4 (LPF) cells. In addition, the economic, environmental, and scarcity risk potential of the products obtained through the best mechanical route were evaluated. The first route involved 6 grinding cycles in a knife mill, followed by particle size separation into 3 fractions. The second route involved a single grinding cycle (knife and hammer mill were tested), followed by particle size separation into 6 fractions. The second route showed more promise, with obtaining fractions rich in (1) iron, (2) aluminum and copper, and (3) cathode materials. Additionally, less operating time and energy consumption were necessary. The hammer mill offered a better separation for the iron and the cathodic materials (LiFePO4), while the knife mill proved to be more effective in concentrating the aluminum and copper. The product potential evaluation of the best route revealed that the priority fractions for recycling in economic and environmental assessment in LFP2 are 2 < n < 9.5mm (due Cu and Al) and n < 0.5mm (due Li). Considering the scarcity risk, priority should be assigned to the recycling of the fraction n < 0.5 due to lithium.

Scalable Production of Thin and Durable Practical Li Metal Anode for High-Energy-Density Batteries.

Utilization of thin Li metal is the ultimate pathway to achieving practical high-energy-density Li metal batteries (LMBs), but its practical implementation has been significantly impeded by formidable challenges of poor thinning processability, severe interphase instability and notorious dendritic Li growth. Here we report a practical thin (10-40 μm) Li/Mo/Li2Se with concurrently modulated interphase and mechanical properties, achieved via a scalable mechanical rolling process. The in-situ generated Li2Se and Mo not only enhance the mechanical strength enabling the scalable fabrication of thin Li metal, but also promote homogenous Li electrodeposition. Significantly, the Li/Mo/Li2Se demonstrates ultrahigh-rate performance (15 mA cm-2) and ultralong-lifespan cycling sustainability (2700 cycles) with exceptional anti-pulverization capability. The Li|LiFePO4 cells show substantially prolonged cyclability over 1200 cycles with an ultralow decay rate of ~0.01% per cycle. Moreover, the Li|LiNi0.8Co0.1Mn0.1O2 pouch cells deliver enhanced cycling stability even under the extremely harsh conditions of low negative-to-positive-capacity (N/P) ratio of ~1.2 and lean electrolyte of ~0.95 g Ah-1, showing an exceptional energy density of 329.2 Wh kg-1. This work sheds light on facile pathway for scalable production of durable thin Li metal anode toward reliable practicability.

Cooperation of metal–organic coordination complex separator and wide-temperature-range electrolyte enables safe and high-performance lithium batteries

With the increase of people’s demand, it is extremely desired for developing high-safety, wide-temperature-range and high-energy-density lithium batteries, but huge challenges are remained due to shrinkage and combustion of commonly used polyolefin separators at high temperatures, as well as narrow usable temperature range and high flammability of conventionally commercialized liquid electrolytes. In this work, we report a multifunctional separator mainly consisting of Zn2+-phytate coordination complex nanoparticles and bacterial cellulose nanofibers, named the BZP separator, which possesses high porosity, excellent thermotolerance, good flame retardancy, abilities of anion binding and Ni2+ capturing. Through cooperating with the fluoride-free wide-temperature-range electrolyte, Li//LiFePO4 cells not only deliver discharge capacities of 110.39 mA h g−1 and 113.25 mA h g−1 after 2200 cycles (2 C) and 1600 cycles (5 C) at 25 °C, with capacity retentions of 76.59% and 86.09%, respectively, but also exhibit excellent cycling performance at 80 °C and −40 °C. Significantly, the Li//NCM811 cell with a loading of 7.8 mg cm−2 delivers a discharge capacity of 146.64 mA h g−1 after 200 cycles at 0.5 C, with a capacity retention of 89.03%. In addition, pouch cells can work at 120 °C and have low flammability.