A flexible high-temperature insulating high entropy ceramic fiber membrane for thermal runaway protection in lithium-ion batteries

Abstract

High-temperature-resistant ceramic fibers are critical materials in emerging applications, including thermal protection for spacecraft, heat exchange systems in petroleum pipelines, thermal insulation in construction, and thermal runaway protection in lithium-ion batteries. However, the brittle failure of oxidized ceramic fibers often leads to structural degradation, limiting their long-term performance at high temperatures. In this study, we present the design of a flexible and durable high-entropy lanthanum zirconate-based silica composite nanofiber membrane, specifically developed for high-temperature thermal protection in lithium-ion batteries. The resultant (La_0.2Ce_0.2Gd_0.2Er_0.2Sm_0.2)₂Zr₂O₇–SiO₂ membrane exhibits an ultra-low thermal conductivity of 0.036 W m⁻¹ K⁻¹ at room temperature and retains good flexibility under 1200 °C. This ceramic membrane also demonstrates exceptional high-temperature insulation performance, with a cold surface temperature of only 332 °C when the hot surface is maintained at 1200 °C, at a thickness of 10 mm. Additionally, the high-entropy ceramic membrane is shown to effectively prevent heat propagation thus secondary explosions in lithium-ion batteries during thermal runaway. This work provides new insight into the rational design of advanced thermal runaway protection for lithium-ion batteries under high temperatures.

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Wenyuan Ma

Dr Wenyuan Ma is an emerging investigator at the Advanced Energy Materials Laboratory, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST). His research focuses on extreme-environment materials, specializing in corrosion-resistant thermal barrier coatings (TBCs), research on high-entropy lanthanum zirconate ceramics (e.g., La2Zr2O7), and electrospun ceramic fibers for thermal management. He develops ceramic membranes preventing thermal runaway in lithium-ion batteries. Dr Ma has published 2 SCI papers on phase stability of high-entropy La2Zr2O7 TBCs and holds 1 patent for flexible high-entropy La2Zr2O7 fiber membranes with high insulation capability.

1. Introduction

In recent years, oxide ceramic nanofiber membranes fabricated via electrospinning technology have attracted considerable attention due to their exceptional properties.^1,2 These membranes exhibit a high surface volume ratio, inherent flexibility, high porosity, and outstanding thermal stability, making them well-suited for a wide range of high-temperature applications, including thermal insulation, flue gas denitrification, shock and noise absorption, as well as protective components in lithium-ion batteries.^3–8 A variety of oxide nanofiber membranes have been successfully prepared using electrospinning, such as Y₂O₃, ZrO₂, Al₂O₃, TiO₂, and SiO₂.^9–14 Notably, ZrO₂/SiO₂, YSZ/SiO₂, and La₂Zr₂O₇ nanofiber membranes have gained significant attention due to their high melting points and superior chemical stability.^15–17 However, their practical applications at temperatures exceeding 1000 °C are limited by the complex phase transitions and grain growth phenomena.¹⁸

Incorporating appropriate second-phase nanoparticles has been shown to effectively enhance the mechanical properties of polycrystalline ceramic fibers, suppress grain growth, and modify their microstructure.^19,20 For instance, the addition of amorphous alumina and silica can effectively inhibit grain growth.²¹ In a zirconia-based system doped with silicon dioxide, zirconia particles are embedded within an amorphous silica matrix, which effectively restricts nucleation and grain growth.²² For example, SiO₂-mullite and SiO₂–ZrO₂ fibers exhibit superior creep resistance compared to pure SiO₂ fibers due to the presence of the second phase.²³ The introduction of 10% ZrO₂ as a second phase even significantly improves the strength of SiO₂ nanofibers.²⁴ A₂B₂O₇-type material like La₂Zr₂O₇ exhibits high-temperature stability, low thermal conductivity, and strong resistance to sintering, enabling them to be promising candidates for high-temperature applications.^25–27 In particular, high-entropy ceramic systems with an A₂B₂O₇ structure demonstrate improved high-temperature phase stability and reduced thermal conductivity compared to yttria-stabilized zirconia (YSZ) and ZrO₂, positioning them as potential candidates for high-temperature ceramic membrane applications.^28,29

However, current research on high-entropy ceramics predominantly focuses on bulk materials and powders, with a limited investigation into high-entropy oxide ceramic fibers.^30–33 For example, Yuan et al. prepared La₂Zr₂O₇ fibers with pyrochlore phase using electrospinning technology pyrochlore.³⁴ Wang et al. prepared silica aerogel with thermal conductivity of 0.057 W m⁻¹ K⁻¹ and good thermal insulation performance.³⁵ A layered ceramic fiber membrane of La₂Zr₂O₇ was reported to show a tensile strength of 1.4 MPa and flexibility of the fiber membrane.¹⁵ However, these reports mainly focus on studying thermal and mechanical performance. Only a few report the use of La₂Zr₂O₇ fibers for thermal runaway protection in lithium-ion batteries.

In this work, we report the fabrication of a flexible high-entropy ceramic nanofiber membrane by electrospinning technology with SiO₂ addition, followed by sintering at high temperatures up to 900 °C. Specifically, the designed (La_0.2Ce_0.2Gd_0.2Er_0.2Sm_0.2)₂Zr₂O₇–SiO₂ composite fiber membrane was prepared with 30% silica. The resultant (La_0.2Ce_0.2Gd_0.2Er_0.2Sm_0.2)₂Zr₂O₇–SiO₂ is abbreviated as LCGESZ–SiO₂. The electrospinning fibers were encapsulated in LCGESZ ceramics containing SiO₂, resulting in fibers with enhanced flexibility. The fiber membrane sintered at 1100 °C exhibits the best flexibility with a stress–strain value of 2.14 MPa. Furthermore, it demonstrates impressive thermal insulation properties, with a low thermal conductivity of 0.04 W m⁻¹ K⁻¹, as well as superior high-temperature resistance. When exposed to a 1200 °C flame from a flame gun, the cold surface temperature of the high-entropy ceramic membrane is only 332 °C at a thickness of 10 mm. More importantly, the high-entropy ceramic membrane can effectively prevent secondary explosions in the thermal runaway environment of lithium-ion batteries. These results suggest that the LCGESZ–SiO₂ fibre membrane is a promising high-temperature resistant material with great potential for battery thermal runaway protection.

2. Materials and methods

2.1. Synthesis and fabrication

The RE(NO)₃·6H₂O (RE = La, Ce, Gd, Er, Sm) (99.99% purity, Aladdin Bio-Chem Technology Co., Ltd, Shanghai, China), Zr(NO₃)₄·5H₂O(99.99% purity, Aladdin Bio-Chem Technology Co., Ltd, Shanghai, China), ethyl orthosilicate (99.99% purity, Aladdin Bio-Chem Technology Co., Ltd, Shanghai, China) alcohol, DMF, acetic acid, polyvinylpyrrolidone were used as received without further treatment. The metal source was dissolved in ethanol in equimolar ratios of La : Ce : Gd : Er : Sm : Zr = 1 : 1 : 1 : 1 : 5. A certain amount of acetic acid, 30 wt% of ethyl orthosilicate, and 10 wt% of PVP were explored as a spinning aid. During the mixing processing, dilute hydrochloric acid (HCl) was introduced to modulate the solution pH, thereby effectively suppressing concentration buildup in the spinning dope that would otherwise impede fiber formation. A transparent and clear precursor spinning solution was prepared by the magnetic stirring of the spinning solution. A high entropy SiO₂ precursor fiber membrane was prepared by electrospinning by injecting a spinning solution into a 10 mL syringe. The spinning voltage is 18 kV and the receiving distance is 20 cm. The spinning precursor fiber membrane was dried in an oven to evaporate residual solvents and was then performed for heat treatment in a muffle furnace. The temperature from room temperature was raised to 600 °C at a rate of 1 °C min⁻¹, and then further increased to 900, 1000, 1100, and 1200 °C at a rate of 5 °C min⁻¹, respectively. The final polycrystalline heated for 2 hours was performed to obtain the LCGESZ–SiO₂ fiber membrane.

2.2. Characterization

The crystal structure of the obtained samples was characterized by X-ray diffraction using a PANalytical X'pert PRO diffractometer with Cu Kα X-ray accelerated in a 2θ range of 10–90°. Nova Nano SEM 450 filed-emission scanning electron microscope (FESEM) was used in obtaining the surface morphology of samples and analysis of the element distribution on the high-entropy pellets surfaces with energy-dispersive X-ray spectroscopy (EDS). High-resolution transmission electron microscopy (HRTEM) was collected on the JEOL JEM-2100 microscope to observe the atomic structure of the high entropy materials. Thermogravimetry analysis (TGA) was used to analyze the thermal stability of ceramic fiber membrane under 10 °C min⁻¹ airflow. The thermal conductivity testing system equipped with an interface thermal resistance meter was explored to measure thermal conductivity. The flexible ceramic film is cut into 20 × 20 mm circular pieces and placed at both ends of the interface thermal resistance meter tablet. The test is carried out according to the program. The mechanical properties of fiber membrane were analyzed using an electronic dynamic and static fatigue testing machine. The high-temperature insulation performance of HELZ-SFM was tested using a FLIR T540 thermal imager.

3. Results and discussion

3.1. LCGESZ–SiO₂ fiber obtained from precursor

The high-entropy lanthanum zirconate based-silica composite fibers were successfully fabricated using electrospinning technology. A homogeneous solution was prepared by dissolving polyvinyl pyrrolidone (PVP), tetraethyl orthosilicate (TEOS), zirconium salts and rare earth salts. The negatively charged oxygen groups on the surface of PVP facilitate strong coordination with metal ions (Zr⁴⁺, RE³⁺, and Si⁴⁺), resulting in the formation of a stable sol through hydrolysis. The solution was then subjected to electrospinning, where an applied electric field induced the stretching and jetting of the charged liquid, leading to the formation of ultrafine nanofiber precursor membranes. These membranes were subsequently dried in an oven to remove the organic solvents. After drying, the fiber membranes were calcined in a muffle furnace to effectively remove the organic components. During the organic matter removal process, crystal nucleation, grain growth, and densification occurred as the oxide ceramic nanofiber felt shrink. During the synthesis process, amorphous SiO₂ fibers were formed, with LCGESZ particles embedded within the silica matrix, derived from rare earth and zirconium ions. The preparation process of LCGESZ nanofibers membrane is illustrated in Fig. 1.

Fig. 1 The procedures of using sol–gel electrospinning to fabricate LCGESZ–SiO₂ membrane.

XRD results (Fig. S1†) show that no crystallization of LCGESZ occurred at 600 °C. Crystallization began to emerge at 800 °C and reached full development by 1100 °C, confirming the complete crystallization process and the successful formation of high-entropy lanthanum zirconate ceramic powder in crystalline form. The high-entropy lanthanum zirconate–silica ceramic fibers started to crystallize at 600 °C, which is significantly lower than the crystallization temperature of high-entropy ceramics prepared via solid-state reaction³⁶ (1100 °C). This may be attributed to the favorable mixing of elements at the molecular level, which reduces the energy barrier for the formation of metal oxides. The TG measurement reveals that the volume exhibited a decreasing trend with increasing temperature (Fig. S2†). Distinct temperature gradients were observed at 80, 200, and 300 °C, respectively. The thermogravimetric analysis indicated that organic matter began to be decomposed at 630 °C, with complete decomposition occurring at 650 °C, resulting in the formation of a ceramic phase. This confirms the formation of ceramics. No further changes in the reaction were observed beyond 700 °C, indicating that the ceramic phase was fully synthesized.

As shown in Fig. 2a–c, the smooth, crack-free surface of the fibers confirms the successful synthesis of a relatively uniform and fine high-entropy lanthanum zirconate based-silica ceramic matrix composite fiber. As the sintering temperature increases, the fiber diameter exhibits a decreasing trend. Specifically, at sintering temperatures of at 1000, 1100, and 1200 °C, the average fiber diameters are measured to be 443, 420, 409 nm, respectively. Fig. 2d presents transmission electron microscopy (TEM) images of LCGESZ–SiO₂ composite fibers at 1000 °C. The outer layer consists of a SiO₂ fiber, while the inner layer contains uniformly dispersed LCGESZ nanoparticles. The grain size of the synthesized high-entropy ceramics ranges from approximately 8 to 10 nm. Fig. 2e displays the corresponding high-resolution transmission electron microscopic (HRTEM) image, in which SiO₂ appears in an amorphous form, while the LCGESZ particles exhibit distinct crystallization. The measured distance of 0.306 nm is attributed to the planar spacing of the (111) plane. The corresponding selected area electron diffractions (SAED) patterns, shown in Fig. 2f, clearly identify the (111), (200) and (220) crystal planes, suggesting that high-entropy LCGESZ particles have a single-phase defect fluorite structure. Fig. 2g shows the EDS spectrum of a single fiber, where the elements of La³⁺, Ce³⁺, Gd³⁺, Er³⁺, Sm³⁺, Zr⁴⁺, and Si⁴⁺ were homogeneously dispersed throughout the LCGESZ–SiO₂ nanofiber.

Fig. 2 SEM images of LCGESZ–SiO₂ fiber at sintering temperature of (a) 1000 °C, (b) 1100 °C, and (c) 1200 °C, (d and e) TEM image of LCGESZ–SiO₂ and (f) corresponding HR-TEM images, and (g) EDS mapping of LCGESZ–SiO₂.

3.2. Mechanical flexibility

Fig. 3a illustrates the overall morphology of the LCGESZ–SiO₂ membrane, revealing that the structure of the membrane is intact and well-formed. The resultant LCGESZ–SiO₂ membrane exhibits good flexibility, retaining its bending properties even after multiple cycles of bending. The tensile stress of the LCGESZ–SiO₂ membrane was evaluated, as shown in Fig. 3b, where the tensile stress of the composite fiber was tested at different temperatures. At 1000, 1100, and 1200 °C, the tensile stresses were 0.84, 2.56, and 1.10 MPa, respectively. The tensile strength of the LCGESZ–SiO₂ nanofibrous membrane heat-treated at 1100 °C reached a maximum value of 2.56 MPa. Notably, at the sintering temperature of 1100 °C, the LCGESZ–SiO₂ membrane exhibits excellent toughness, which is mainly attributed to the high degree of crystallization. As shown in Fig. S3a,† the crystallization significantly improved the mechanical properties of the composite fiber. The formation of particle-enriched phases within the fibers improves the mechanical properties and strength, resulting in superior overall performance. As the heat treatment temperature rose, the crystallinity gradually improved, the grain structure grew denser, and the interfacial bonding between the LCGESZ and silica fibers strengthened. However, at 1200 °C, the fracture toughness significantly decreases. When prepared at 1100 °C, the LCGESZ–SiO₂ particles had an average grain size of 9 nm. In contrast, at 1300 °C, the LCGESZ crystals showed significant growth, with the average grain size increasing to 38 nm (Fig. S3b†). Consequently, this results in a decrease in the strength of the LCGESZ–SiO₂ membrane and an increase in brittleness. After high-temperature calcination at 1200 °C for 24 h, tensile tests were conducted at 5, 15, 25, 35, and 45 cycles with 8% strain (Fig. 3c). After 45 cycles, the maximum stress remained at 4.23 MPa, demonstrating the ceramic membrane's excellent tensile properties. As shown in Fig. 3d, the fiber membrane also exhibited exceptional bending performance under the flame spray gun, confirming that the LCGESZ–SiO₂ membrane maintains strong flexural strength even at extremely high temperatures.

Fig. 3 (a) Reflexibility of the LCGESZ–SiO₂ membrane, (b) the tensile strength of the membrane, (c) tensile test diagram of the membrane, (d) bending image of the membrane under the flame spray gun, (e) schematic diagram of flexibility enhancement mechanism.

The mechanism for the improvement in the mechanical properties of the LCGESZ–SiO₂ membrane is illustrated in Fig. 3e. When stress concentrates in the bending region, large cracks and nanoscale voids rapidly propagate and coalesce into larger cracks and voids, leading to SiO₂ fiber fracture. In the case of the LCGESZ–SiO₂ fibers, on the one hand, the presence of LCGESZ–SiO₂ particles reduces the size of defect flaws within the fiber.³⁷ By forming a strong interfacial bond with SiO₂, the particles promote a more uniform stress distribution across the fiber, mitigating stress concentration in localized areas. Additionally, nanoscale cracks are confined around the particles, effectively inhibiting the propagation of macroscopic cracks. These nanoscale cracks also contribute to energy dissipation; during fiber deformation, they absorb a portion of the bending stress energy, reducing the energy required for fiber fracture. This mechanism enhances the fiber's durability and resistance under high-stress conditions.

4. High-temperature insulation

To assess the high-temperature thermal insulation performance of the ceramic fiber membrane, the LCGESZ–SiO₂ membrane was subjected to a flame spray gun, and the temperature on its backside was measured using a handheld infrared thermometer. As shown in Fig. 4a, as the ablation time increased, the average temperature on the backside of the 10 mm LCGESZ–SiO₂ membrane was 76 °C at 60 s, 126 °C at 60 s, 305 °C at 180 s, and 332 °C at 600 s (Fig. 4b–e). After ablation, the LCGESZ–SiO₂ membrane retained its intact morphology. As shown in Fig. S4,† the fibers did not break and maintained a relatively long length, which remained unchanged from the original fiber. Owing to the high-temperature resistance of LCGESZ fibers, no fractures occurred between individual fibers. Overall, the temperature decreased from 1200 to 332 °C, representing a temperature reduction of 868 °C (Fig. 4f), which demonstrates the good thermal insulation properties of the membrane. The microstructure characterization of the material after 12 h thermal treatment at 1400 °C was investigated (Fig. S5†). As evidenced by the experimental results, although distinct localized adhesion phenomena were observed at fiber bundle contact regions, the majority of fibrous structures maintained their fundamental morphological integrity under extreme thermal conditions.

Fig. 4 (a) Schematic representation of flame torch-induced ablation on ceramic membranes, infrared thermal imaging display in different time of (b) 60 s, (c) 120 s, (d) 180 s, and (e) 600 s. (f) Temperature difference between the heat source side and the back side of the ceramic membrane.

The thermal conductivity of the LCGESZ–SiO₂ membrane was measured to be 0.036 W m⁻¹ K⁻¹. Compared with the thermal conductivity of conventional ZrO₂–SiO₂ ceramic fiber membrane (0.046 W m⁻¹ K⁻¹), the thermal conductivity of the LCGESZ–SiO₂ ceramic fiber membrane was reduced by 21.7%.³⁸ It can be attributed to enhanced phonon scattering.³⁹ The high-entropy LSGESZ composition, which contains multiple elements and a complex structure, introduces lattice defects, impurities, and irregularities. These features significantly increase phonon scattering, resulting in a reduction in thermal conductivity.⁴⁰ Lanthanum zirconate has a high melting point of approximately 2600 °C, which allows it to maintain structural stability even at extremely high temperatures, preventing it from melting or decomposing.⁴¹ The significant differences in ionic radii between Zr ⁴⁺ and La³⁺, Ce³⁺, Gd³⁺, Er³⁺, and Sm³⁺ help to stabilize the lattice structure of lanthanum zirconate. The distinct positioning of zirconium and lanthanum ions within the lattice facilitates their interactions, effectively maintaining the structural stability of the crystal at high temperatures.⁴² Compered to the traditional ceramic membrane like SiO₂ (withstand 700 °C)¹² and Al₂O₃ (withstand 800 °C)⁴³ membrane, the LCGESZ–SiO₂ membrane has improved temperature resistance by 74.1% and 50%, respectively. These strong bonds is favorable for the high thermal stability of the membrane. This finding confirms that the LSGESZ–SiO₂ composite ceramic membrane exhibits impressive high-temperature resistance, providing effective thermal protection performance.

In the alcohol lamp burning experiment, ablation tests were performed on both commercially available ceramic fiber membrane and the self-prepared LSGESZ–SiO₂ fiber membranes. As shown in Fig. 5a and b, the commercially available ceramic fiber membrane underwent continuous combustion when exposed to the flame. The membrane ignited after 2 seconds, with the organic matrix beginning to degrade at 5 seconds, causing the membrane to blacken. By 15 seconds, significant combustion was observed across the entire ceramic membrane matrix, and by 30 seconds, the matrix had nearly completely burned away, leaving a visibly charred surface. The commercially available ceramic membrane exhibited a mass loss of 14.42%, highlighting its poor fire resistance. In contrast, under identical experimental conditions, the self-prepared LSGESZ–SiO₂ ceramic membrane showed no visible changes in appearance or structural damage during 1 to 30 s exposure to the alcohol lamp flame. No quality change was observed in the ceramic membrane, indicating superior ablation resistance. After the burning experiment, the tensile strength of the membrane was measured to be 2.36 MPa. These results suggest that the self-prepared LSGESZ–SiO₂ fiber membrane exhibits significantly better thermal stability in high-temperature environments, demonstrating the enhanced heat resistance and antioxidative properties compared to the commercially available ceramic fiber membrane.

Fig. 5 (a) Demonstration image of commercial fiber membrane under alcohol spray lamp, (b) demonstration image of LCGESZ–SiO₂ membrane under alcohol spray lamp.

5. Battery thermal runaway protection

To evaluate the protective performance of high-entropy ceramic membranes in lithium-ion batteries, a testing platform was built, as illustrated in the schematic diagram (Fig. 6a).⁴⁴ In this experimental setup, a lithium-ion battery was positioned on a heating stage. In one group, a second lithium-ion battery was staked directly on top of the first, while in the other group, the LSGESZ–SiO₂ membrane was placed between the two batteries, with the second battery stacked above the membrane. The heating process occurred in several stages. At 168 s, as the temperature of the bottom battery rose, the electrolyte—a typical organic solvent containing lithium salts—began to evaporate (Fig. 6b). This evaporation caused a gradual increase in internal pressure, leading to the expansion of the bottom battery. By 212 to 228 s, the internal temperature reached a critical threshold, triggering thermal runaway (Fig. 6c and d). Thermal runaway is a self-accelerating process involving chemical reactions and physical changes within the battery, resulting in a rapid temperature increase and the release of large volumes of gas. This process persisted in the bottom battery until thermal runaway subsided. At 309 s, heat from the bottom battery transferred to the upper battery (Fig. 6e). In the unprotected group, the upper battery experienced secondary thermal runaway, characterized by swelling and smoke emission. In contrast, the upper battery in the LSGESZ–SiO₂ membrane-protected group showed no visible changes. Over time, thermal runaway intensified in the unprotected group, while the upper battery in the membrane-protected group remained stable, with no signs of thermal runaway (Fig. 6f and g). By 600 s, after the high-temperature thermal runaway event, both batteries in the unprotected group were severely compromised, undergoing violent chemical reactions. In contrast, the upper battery in the membrane-protected group remained structurally intact, showing no signs of thermal runaway (Fig. 6h). Fig. 6i provides a comparison between the two groups. In the unprotected group, both batteries combusted, releasing substantial heat and smoke. Conversely, the LSGESZ–SiO₂-protected group effectively insulated the upper battery from high temperatures, preventing secondary thermal runaway and ensuring the upper battery remained unaffected despite the thermal runaway in the bottom battery.

Fig. 6 (a) Experimental schematic diagram, (b) schematic pictures of battery protection under heating time: (b)168 s, (c) 212 s, (d) 228 s, (e) 309 s, (f) 318 s, (g) 362 s, (h) 600 s, (i) comparison pictures with and without membrane protection, (j) the Li-ion battery is protected by LSGESZ–SiO₂ membrane and placed on a heating table (k) corresponding infrared thermal imaging image (l) the temperature rise curve of the Li-ion battery of the LZFM with a thickness of 3 mm.

The corresponding infrared thermal imaging image shows that the thermal insulation membrane isolates the bottom heat source from the battery, with heat concentrated at the bottom adjacent to the heating table (Fig. 6j–l). This prevents heat from transferring upward to the upper battery, providing effective battery protection. When the bottom temperature reached 260 °C, the temperature of the upper battery gradually increased over time. After reaching 230 s, the temperature stabilized, and the final battery temperature remained at 58 °C, well below the thermal runaway threshold of 130 °C.⁴⁵ To describe the variation of the membrane's temperature for time in the experiment, we applied Newton's Law of Heating,⁴⁶ which is expressed by the following equation:

Here, T(t) represents the temperature of the membrane at time, T_env is the ambient temperature, and k is the heat exchange constant. The analytical solution to this equation is given by:

T(t) = T_env − (T_env − T₀)e^−kt (2)

The fitted ambient temperature is 58.0 °C, the initial temperature is 24.0 °C, and the heat exchange constant is 0.0056. This indicates that the temperature at the top of the membrane gradually approaches 58 °C over time and eventually stabilizes around that value. This temperature change pattern conforms to the expectations of Newton's heating law.

T(t) = 58 − (58 − 24.06)e^−0.0056t (3)

These results demonstrate that the LSGESZ–SiO₂ membrane effectively mitigates the chain reaction of thermal runaway, providing enhanced protection for lithium-ion batteries.

6. Conclusions

In this study, a flexible high-entropy ceramic nanofiber membrane was successfully fabricated using electrospinning technology with the incorporation of SiO₂, followed by high-temperature sintering up to 1100 °C. Specifically, an LCGESZ–SiO₂ composite fiber membrane with 30% SiO₂ content was synthesized. The electrospun fibers, encapsulated within LCGESZ ceramics containing SiO₂, exhibited enhanced flexibility. The membrane sintered at 1100 °C demonstrated optimal flexibility, with a stress–strain value of 2.56 MPa. Additionally, it displayed remarkable thermal insulation properties, including a low thermal conductivity of 0.036 W m⁻¹ K⁻¹, and exceptional high-temperature resistance. When exposed to a 1200 °C flame from a flame gun, the cold surface temperature remained at only 332 °C. The high-entropy ceramic membrane also proved effective in preventing secondary explosions in lithium-ion battery thermal runaway scenarios. These findings highlight the LCGESZ–SiO₂ membrane as a promising high-temperature-resistant material with significant potential for protecting against lithium-ion battery thermal runaway.

Data availability

The data supporting this article have been included as part of the ESI.†

Conflicts of interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This work was supported by the National Natural Science Foundation of China under Grant No. 52271215 and 92163211, the Fundamental Research Funds for the Central Universities under Grant No. 2024BRB010. Q. Liang acknowledges the financial support from the Natural Science Foundation of Jiangxi province (No. 20232ACB214001) and Chinese Academy of Sciences.

References

1. V. Vatanpour, B. Kose-Mutlu and I. Koyuncu, Desalination, 2022, 533, 115765.
2. H. Liu, N. Wu, X. Zhang, B. Wang and Y. Wang, Ceram. Int., 2022, 48, 34169–34183.
3. X. Wan, Y. Zhao, Z. Li and L. Li, Exploration, 2022, 2, 20210029.
4. Y. Xing, W. Dan, Y. Fan and X. a. Li, J. Mater. Sci. Technol., 2022, 103, 215–220.
5. M. Zhang, L. Yao, Y. Xing, J. Cheng, T. Yang, J. Liu and W. Pan, J. Mater. Sci. Technol., 2024, 181, 189–197.
6. M. Biesuz, T. Saunders, D. Ke, M. J. Reece, C. Hu and S. Grasso, J. Mater. Sci. Technol., 2021, 69, 239–272.
7. A. K. Mishra, Monika and B. S. Patial, Mater. Today Energy, 2024, 7, 100089.
8. S. Guo, L. Jiang, Y. Li, P. Zhong, S. A. Ismail, T. Norby and D. Han, Adv. Funct. Mater., 2024, 34, 2304729.
9. C. H. Kirk, P. Wang, C. Y. D. Chong, Q. Zhao, J. Sun and J. Wang, J. Mater. Sci. Technol., 2024, 183, 152–164.
10. X. Dong, Q. An, S. Zhang, H. Yu and M. Wang, Ceram. Int., 2023, 49, 31035–31045.
11. Z. Deng, Y. Xie, W. Liu, J. Dong, Y. Peng, Z. Zhu, L. Zhu, G. Zhang, X. Wang and D. Xu, Ceram. Int., 2022, 48, 16715–16722.
12. M. Yang, Y. Lixia, Z. Chen, W. Qiong, Y. Wang, T. Liu and M. Li, Ceram. Int., 2023, 49, 9165–9172.
13. L. Xu, Z. Deng, Y. Wang, D. Ma, B. Liu, G. Zhang, X. Wang, L. Zhu and D. Xu, Ceram. Int., 2024, 50, 14520–14528.
14. Y. Xin, Q. Wang, C. Fu, S. Du, L. Hou, X. Wei, H. Wang and X. Wang, Adv. Funct. Mater., 2025, 35, 2413813.
15. D. Ma, Y. Xie, L. Wang, Y. Peng, Y. Yin, X. Wang, B. Liu, G. Zhang, L. Zhu and D. Xu, Chem. Eng. J., 2023, 468, 143488.
16. Y. Peng, Y. Xie, L. Wang, L. Liu, S. Zhu, D. Ma, L. Zhu, G. Zhang and X. Wang, J. Eur. Ceram. Soc., 2021, 41, 1471–1480.
17. Y. Deng, B. Ren, Y. Jia, Q. Wang and H. Li, J. Mater. Sci. Technol., 2024, 196, 50–59.
18. X. Zhang, X. Wang, W. Jiao, Y. Liu, J. Yu and B. Ding, J. Eur. Ceram. Soc., 2023, 43, 1255–1269.
19. F. Zhang, Y. Si, J. Yu and B. Ding, Chem. Eng. J., 2023, 456, 140989.
20. X. Liang, Q. Sun, X. Zhang, Z. Hu, M. Liu, P. Gu, X. Yang and G. Zu, Adv. Funct. Mater., 2024, 34, 2408707.
21. L. Zhan, F. Zhang, Q. Liu, J. Wang, C. Wu, S. Yao, Y. Ma and W. Liu, J. Eur. Ceram. Soc., 2023, 43, 7023–7032.
22. X. Zhang, X. Cheng, Y. Si, J. Yu and B. Ding, Chem. Eng. J., 2022, 433, 133628.
23. J. Zhong, N. Li, X. Xu, L. Wei, H. Liu, H. Li, Z. Fang and H. Bao, Ceram. Int., 2023, 49, 16283–16289.
24. Q. Wu, Z. Chen, Y. Ding, L. Yin, M. Yang, D. E. Erişen, T. Liu, M. Li, L. Yang and S. Cui, Ceram. Int., 2024, 50, 55–64.
25. Y. Jing, Y. Fang, X. Cui, Z. Chen, D. Liu, A. Liu, X. Wang, Q. Li, G. Jin and H. Tian, Tribol. Int., 2023, 185, 108551.
26. N. K. Gopinath, A. Dan, S. T. Aruna, K. V. Govindarajan, G. Jagadeesh, H. C. Barshilia and D. Roy Mahapatra, Appl. Surf. Sci., 2024, 652, 159324.
27. X. Cao, Y. Li, Y. Chen, G. Brewster, D. A. Hall, S. J. Haigh, J. P. Martins and P. Xiao, Scr. Mater., 2025, 255, 116374.
28. Y. Jiao, J. Dai, Z. Fan, J. Cheng, G. Zheng, L. Grema, J. Zhong, H.-F. Li and D. Wang, Mater. Today, 2024, 77, 92–117.
29. K. Zhang, X. Duan, M. Jiang, X. Liu, Z. Qian, Q. Zhang and Y. Qiao, Ceram. Int., 2024, 50, 52640–52648.
30. M. Zhang, J. Ye, Y. Gao, X. Duan, J. Zhao, S. Zhang, X. Lu, K. Luo, Q. Wang, Q. Niu, P. Zhang and S. Dai, ACS Nano, 2024, 18, 1449–1463.
31. Z. Deng, Y. Peng, W. W. Qin, B. Liu, G. Zhang, X. Wang, Y. Xie, L. Zhu and D. Xu, Chem. Eng. J., 2023, 475, 146260.
32. L.-Y. Li, M. Zhang, M. Jiang, L.-H. Gao, Z. Ma and M.-S. Cao, Adv. Funct. Mater., 2024, 2416673.
33. B. Ma, Y. Yan, M. Wu, S. Li, M. Ru, Z. Xu and W. Zhao, Adv. Funct. Mater., 2025, 35, 2413814.
34. K. Yuan, C. Feng, X. Gan, Z. Yu, X. Wang, L. Zhu, G. Zhang and D. Xu, Ceram. Int., 2016, 42, 16633–16639.
35. Y. Wang, Y. Yu, F. Tu, L. Huang, D. Ye, Z. Fu and S. Zhao, J. Non-Cryst. Solids, 2024, 625, 122772.
36. L. Zhou, F. Li, J.-X. Liu, Q. Hu, W. Bao, Y. Wu, X. Cao, F. Xu and G.-J. Zhang, J. Eur. Ceram. Soc., 2020, 40, 5731–5739.
37. N. Wu, B. Wang and Y. Wang, J. Am. Ceram. Soc., 2018, 101, 4763–4772.
38. J. He, H. Zhao, X. Li, D. Su, H. Ji, H. Yu and Z. Hu, Ceram. Int., 2018, 44, 8742–8748.
39. J. Che, X. Liu, X. Wang, K. P. Furlan and S. Zhang, Ceram. Int., 2023, 49, 10936–10945.
40. J. Che, W. Huang, G. Ren, J. Linghu and X. Wang, Ceram. Int., 2024, 50, 22865–22873.
41. M. Mathanbabu, D. Thirumalaikumarasamy, P. Thirumal and M. Ashokkumar, Mater. Today: Proc., 2021, 46, 7948–7954.
42. D. Liu, Y. Li, C. Liu and B. Li, J. Colloid Interface Sci., 2023, 636, 588–601.
43. H. Xu, C. Liu, W. Guo, N. Li, Y. Chen, X. Meng, M. Zhai, S. Zhang and Z. Wang, Chem. Eng. J., 2024, 489, 151223.
44. Z. Wang, H. Yang, Y. Li, G. Wang and J. Wang, J. Hazard. Mater., 2019, 379, 120730.
45. D. Hu, S. Huang, Z. Wen, X. Gu and J. Lu, Renewable Sustainable Energy Rev., 2024, 206, 114882.
46. S. Maruyama and S. Moriya, Int. J. Heat Mass Transfer, 2021, 164, 120544.

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Footnote

† Electronic supplementary information (ESI) available. See DOI: https://doi.org/10.1039/d5ta02532j

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