Cycling Stability Research Articles

High-voltage and dendrite-free zinc-iodine flow battery

Zn-I2 flow batteries, with a standard voltage of 1.29 V based on the redox potential gap between the Zn2+-negolyte (−0.76 vs. SHE) and I2-posolyte (0.53 vs. SHE), are gaining attention for their safety, sustainability, and environmental-friendliness. However, the significant growth of Zn dendrites and the formation of dead Zn generally prevent them from being cycled at high current density (>80 mA cm−2). In addition, the crossover of Zn2+ across cation-exchange-membrane also limits their cycle stability. Herein, we propose a chelated Zn(P2O7)26- (donated as Zn(PPi)26-) negolyte, which facilitates dendrite-free Zn plating and effectively prevents Zn2+ crossover. Remarkably, the utilization of chelated Zn(PPi)26- as a negolyte shifts the Zn2+/Zn plating/stripping potential to −1.08 V (vs. SHE), increasing cell voltage to 1.61 V. Such high voltage Zn-I2 flow battery shows a promising stability over 250 cycles at a high current density of 200 mA cm−2, and a high power density up to 606.5 mW cm−2.

Mg ions intercalated with V3O7·H2O to construct ultrastable cathode materials for aqueous zinc-ion batteries.

V3O7·H2O (VO) stands out as a highly promising cathode material for aqueous zinc-ion batteries (AZIB). However, due to the instability of the VO structure and the limited ion transport rate, achieving the required specific capacity and extended cycling lifespan has been challenging. To tackle this issue, we synthesized Mg-ion intercalated VO (MgVO) using a straightforward hydrothermal method. Introducing Mg2+ as an interlayer support enhanced the flexibility of MgVO within the confined layer space, stabilized its lamellar structure, and expanded the VO layer spacing. The AZIB employing the MgVO cathode demonstrated a high specific capacity of 382.7 mA h g-1 at a current density of 0.1 A g-1 and showed excellent cycling stability. The robust structural stability of MgVO suggests promising applications for large-scale energy storage, while the Mg2+ intercalation strategy presents a novel approach for exploring other potential cathode materials.

Favored Amorphous LixSi Process with Restrained Volume Change Enabling Long Cycling Quasi-solid-state SiOx anode.

Silicon-based anodes are becoming promising materials due to their high specific capacity. However, the intrinsically large volume change brought about by the alloying reaction results in the crushing of the active particles and destruction of the electrode structure, which severely limits its practical application. Various structured and modified silica-based anodes exhibit improved cycling stability and the demonstrated ability to mitigate their volume changes through interfacial and binder strategies. However, the issue of large volume changes in silicon-based anodes remains. Herein, we report a gel polymer electrolyte (GPE) prepared through an in situ thermal polymerization process that is suitable for SiOx anode materials and achieving long-term cycling stability. GPE-based cells essentially mitigate the volume change of SiOx anodes by guiding the unique lithiation/delithiation mechanism that tends to favor the formation and delithiation of amorphous-LixSi (a-LixSi) with smaller volume change, thereby mitigating electrode damage and cracking, and achieving the significant improvement in cycling performance. The prepared GPE-SiOx cells retained 693.80 mAh g-1 reversible capacity after 450 cycles at 500 mA g-1. In addition, the prelithiation process was incorporated to mitigate capacity fluctuations and improve the Initial Coulombic Efficiency (ICE), and a reversible capacity of 641.90 mAh g-1 was retained after 480 cycles.

Multi-layered carbon accommodation of MnO2 enabling fast kinetics for highly stable zinc ion batteries

Large-scale durable aqueous zinc ion batteries for stationary storage are realized by spray-coating conductive PEDOT(Poly(3,4-ethylenedioxythiophene)) wrapping MnO2/carbon microspheres hybrid cathode in this work. The porous carbon microspheres with multiple layers deriving from sucrose provide suitable accommodation for MnO2 active materials, exposing more redox active sites and enhancing the contact surface between electrolyte and active materials. As a result, MnO2/microspheres are adhered to the current collector by a conductive PEDOT coating without any binder. The ternary design retards the structural degradation during cycling and shortens the electron and ion transport path, rendering the full batteries high capacity and long cycle stability. The resulting batteries perform the capacity of 277, 227, 110, 85 and 50 mAh/g at 0.2, 0.5, 1, 2 and 5 A/g, respectively. After 3000 cycles the initial capacity retains 86%, and 80% after 5000 cycles. GITT indicates PEDOT wrapping MnO2/microspheres cathode enables better ion intercalating kinetics than conventional MnO2. The work could represent a novel and significant step forward in the studies on the large-scale application of zinc ion batteries.

Highly Performing Sodium Metal Batteries Reinforced by a Self-Regulated Dual-Layered Solid Electrolyte Interphase via a Metal-Organic Framework.

Sodium-metal batteries, heralded for high energy density and cost-effectiveness, are compromised by an unstable solid electrolyte interphase (SEI) and dendrite formation, which hinder practical applications. Herein, a zirconium-based metal-organic framework nanostructure coating (ZMOF-NSC) was constructed in a low-loss, flexible manner. Comprehensive studies show that ZMOF-NSC, with its periodically ordered nanochannels and organized pore structures, enhances ion transport and decreases the Na+ migration energy barrier, thus ensuring uniform ion flux and achieving uniform spherical deposition. Additionally, ZMOF-NSC facilitates partial desolvation, catalyzing the formation of an inorganic-rich, dual-layered SEI that effectively protects the anode and suppresses dendrite formation. Consequently, the ZMOF-NSC@Na symmetric battery exhibits an impressive lifespan of over 2500 h, demonstrating extended operational longevity. The Na3V2(PO4)3∥ZMOF-NSC@Na batteries demonstrate exceptional cycling stability with 81% capacity retention after 2000 cycles at 10 C, maintaining stability over 3000 cycles at 20 C. Moreover, the NVP∥ZMOF-NSC@Na battery achieves an energy density of 370 Wh kg-1 and a power density of 10,484 W kg-1, indicating superior durability and performance. This significant finding highlights the significant potential of structured MOFs to induce a dual-layered SEI, advancing the commercialization of durable, dendrite-free sodium metal batteries. The precise design of self-assembled pore structures and surface active sites in MOFs demonstrates significant potential in advancing the commercialization of durable, dendrite-free electrodes of metal-based rechargeable batteries.

Effect of plant development on phosphorus fractions and microbial phosphorus cycle in subsurface flow constructed wetlands

Plant development can influence the effluent concentrations of total phosphorus (TP) in constructed wetlands (CWs). However, little is known regarding the effect of plant development on P cycling in CWs. In this study, Juncus effusus was selected as wetland plant. The P removal efficiency, the change of P fractions in substrate and the relative abundance of P cycling genes were investigated along with plant development in CWs over seedling, mature, and wilting stages. The results showed that the effluent concentration of TP in CWs varied towards higher levels along with the plant development, and significant differences from the previous two stages were observed at the wilting stage. P fractions in the substrate accumulated with continuing influent, providing conditions for P cycling. There were differences in the relative abundance of functional genes involved in P cycling at different stages of plant development. With plant development, microbial transportation of P (indicated by the genes of phnCDE and ugpABCE) was weakened and then enhanced, while in contrast inorganic P solubilization (indicated by the genes of gcd) and organic P mineralization (indicated by the genes of phnP and phnW) were enhanced and then weakened. Pearson correlation analysis results indicated that the P cycling in the substrate of CWs was enriched with plant development, which promoted labile P accumulation in the CW substrate, resulting in higher effluent TP concentration at the wilting stage. Plant development was found to influence P cycling related microbes by regulating the relative abundance of genes involved in P cycling. The acquired results provided new insights into the effect of plant development on P cycling and effluent TP concentration stabilization in CWs.

Novel three-dimensional architectured ZnMgAl ternary layered double hydroxide@reduced graphene oxide nanocomposites as electrode material for high-performance supercapacitor

Ternary layered double hydroxides (LDH) have recently attracted immense attention owing to their stupendous features, such as fine compositional tuning, multiple valence states, and superior electrochemical activity. Moreover, their intriguing structures and distinctive physiochemical properties delineate them as an exemplary material to serve as electrodes for high-performance supercapacitors (SCs). The present work reports the in-situ synthesis of Zinc Magnesium Aluminium LDH (ZMA) integrated with reduced graphene oxide (rGO) through a single-step hydrothermal approach. The resulting novel ternary ZMA@rGO nanocomposite (ZMAG) possesses a unique architecture incorporating hierarchical 3D nanoflowers of ZMA embedded on graphene nanosheets. The porous morphology of LDH improves interfacial charge transport, which results in more faradaic reactions at the electrochemically active sites. In addition, the conductive graphene nanosheets render a high specific surface area, endowing excellent capacitive behavior. The amalgamated electrochemical properties of ZMA and rGO develop a competent electrode material (ZMAG) for SCs. The ZMAG2 nanocomposite having ZMA and rGO in 1:1, evinces a specific capacitance (Cs) of 656.7 F/g at a current density (Id) of 1 A/g. Furthermore, the asymmetric supercapacitor (ASC) features admirable cycle stability (retains 89% of initial capacitance after 15,000 charge/discharge cycles). Herein, the real-time application of ZMA@rGO//AC ASC has also been demonstrated. Therefore, hierarchical porous nanostructure proclaims new prospects for fabricating proficient electrode materials for energy storage devices.

Dual carbon protected ultrafine SnO2 nanoparticles with Sn–C interface for robust lithium storage

Stannic oxide (SnO2)-based lithium-ion batteries (LIBs) have garnered tremendous attention due to their high theoretical capacity and suitable lithium ion insertion potential. However, their widespread applications have been hindered by severe electrode degradation caused by substantial volume expansion of SnO2. In this study, we embedded amorphous carbon encapsulated ultrafine SnO2 nanoparticles on hollow macroporous carbon (AC@SnO2/HMC) as a superior anode material for LIBs. The unique Sn–C interface and dual carbon protection layers effectively mitigated SnO2 nanoparticle agglomeration and volume expansion, reinforcing the cycling stability. Additionally, the capacitive contribution from amorphous carbon significantly improved the reversible capacity and rate capability. As such, the resulting AC@SnO2/HMC electrode exhibited high capacity (1828 mAh g−1 after 200 cycles at 0.1 A g−1), excellent rate capability (1017.6 mAh g−1 at 1 A g−1), and outstanding cycling performance (792.1 mAh g−1 after 880 cycles at 2 A g−1), surpassing previously reported SnO2-based anodes. Furthermore, the AC@SnO2/HMC-based Li-ion full cell demonstrated a remarkable capacity of 566.3 mAh g−1 at 0.2 A g−1 after 200 cycles. This study offers valuable insights into the development of advanced SnO2-based anodes for LIBs and beyond, highlighting their potential for future advancements in battery technology.

Colloidally synthesized Cu3VS4 nanocrystals as a long cycling anode material for sodium-ion batteries

We report on the colloidal synthesis of Cu3VS4 nanocrystals as an earth abundant anode material for sodium-ion battery applications. The nanocrystals were structurally characterized prior to testing in half-cells, where they displayed excellent cycling stability up to 1000 cycles, demonstrating the potential of colloidally synthesised materials for sustainable battery applications.

Synergistic enhancement of cathode/anode interfaces with high water-retentive organohydrogel enabling highly stable zinc ion batteries

Current aqueous battery electrolytes, including conventional hydrogel electrolytes, exhibit unsatisfactory water retention capabilities. The sustained water loss will lead to subsequent polarization and increased internal resistance, ultimately resulting in battery failure. Herein, a double network (DN) organohydrogel electrolyte based on dimethyl sulfoxide (DMSO)/H2O binary solvent was proposed. Through directionally reconstructing hydrogen bonds and reducing active H2O molecules, the water retention ability and cathode/anode interfaces were synergistic enhanced. As a result, the synthesized DN organohydrogel demonstrates exceptional water retention capabilities, retaining approximately 75% of its original weight even after the exposure to air for 20 days. The Zn||MnO2 battery delivers an outstanding specific capacity of 275 mA h g−1 at 1 C, impressive rate performance with 85 mA h g−1 at 30 C, and excellent cyclic stability (95% retention after 6000 cycles at 5 C). Zn||Zn symmetric battery can cycle more than 5000 h at 1 mA cm−2 and 1 mA h cm−2 without short circuiting. This study will encourage the further development of functional organohydrogel electrolytes for advanced energy storage devices.

Transforming Zinc-Ion Batteries with DTPA-Na: A Synergistic SEI and CEI Engineering Approach for Exceptional Cycling Stability and Self-Discharge Inhibition.

Aqueous zinc-ion batteries (ZIBs) hold immense promise for large-scale energy storage, but their practical application is hindered by zinc anode limitations. We introduce diethylenetriamine pentaacetate sodium salt (DTPA-Na) as a novel electrolyte additive to address these challenges. DTPA-Na's unique dual functionality enables the formation of robust, multi-layered solid electrolyte interphases (SEI) on the zinc anode and stable cathode electrolyte interphases (CEI) on the MnOOH cathode. This synergistic SEI/CEI engineering approach effectively suppresses interfacial side reactions, promotes uniform zinc deposition, and inhibits dendrite growth, leading to exceptional cycling stability and self-discharge inhibition. Asymmetrical cells employing DTPA-Na achieve an unprecedented 32,000 cycles at a high charging rate of 50 mA/cm2, while symmetric cells demonstrate a lifespan of 160 hours with 95% zinc utilization. Full Zn||MnOOH cells exhibit remarkable stability, maintaining 98.61% capacity retention after 720 hours of self-discharge and negligible capacity decay over 5000 cycles. Our work highlights the transformative potential of DTPA-Na as a dual-functional electrolyte additive, paving the way for high-performance ZIBs for practical energy storage applications.

Transforming Zinc‐Ion Batteries with DTPA‐Na: A Synergistic SEI and CEI Engineering Approach for Exceptional Cycling Stability and Self‐Discharge Inhibition

Aqueous zinc‐ion batteries (ZIBs) hold immense promise for large‐scale energy storage, but their practical application is hindered by zinc anode limitations. We introduce diethylenetriamine pentaacetate sodium salt (DTPA‐Na) as a novel electrolyte additive to address these challenges. DTPA‐Na's unique dual functionality enables the formation of robust, multi‐layered solid electrolyte interphases (SEI) on the zinc anode and stable cathode electrolyte interphases (CEI) on the MnOOH cathode. This synergistic SEI/CEI engineering approach effectively suppresses interfacial side reactions, promotes uniform zinc deposition, and inhibits dendrite growth, leading to exceptional cycling stability and self‐discharge inhibition. Asymmetrical cells employing DTPA‐Na achieve an unprecedented 32,000 cycles at a high charging rate of 50 mA/cm2, while symmetric cells demonstrate a lifespan of 160 hours with 95% zinc utilization. Full Zn||MnOOH cells exhibit remarkable stability, maintaining 98.61% capacity retention after 720 hours of self‐discharge and negligible capacity decay over 5000 cycles. Our work highlights the transformative potential of DTPA‐Na as a dual‐functional electrolyte additive, paving the way for high‐performance ZIBs for practical energy storage applications.

In‐situ Construction of Self‐Healing Polyelectrolyte/Polyzwitterion Coacervate Framework for High‐Performance Silicon Anodes

AbstractSilicon is considered as a promising candidate for anode materials due to its ultrahigh theoretical capacity and natural abundance. However, the commercialization is severely hampered by the large strain and short cycle life. Herein, we have synthesized a reversible polyelectrolyte/polyzwitterion coacervate framework to achieve high‐performance silicon anodes with high initial Coulombic efficiency (ICE) and stable cyclability. Such coacervate framework is formed via in‐situ free radical polymerization of zwitterionic 2‐methacryloyloxy ethyl phosphorylcholine (MPC) with polyacrylic acid (pAA) during heating the slurry. The resulting pAA/pMPC coacervate framework presents excellent adhesion, thermal stability, and negligible swelling in the electrolyte. Comparing with pAA, pAA/pMPC0.1 coacervate framework binder exhibits superior performance during charge/discharge. The ICE is improved from 84.41 %, to 87.61 %. After 250 cycles, the specific capacity of pAA/pMPC0.1 silicon anode is 1678 mAh g−1 with a retention of 78 % while the pAA silicon anode completely failed after less than 200 cycles. Such improvement is ascribed to the structural integrity of the electrode endowed by the self‐healing ability of pAA/pMPC coacervate framework. This work not only offers a feasible method to in‐situ construct coacervate framework with self‐healing capability to achieve high‐performance silicon anodes but also a compatible electrode preparation process for other high‐capacity materials.

Fence‐type Molecular Electrocatalysts for High‐Performance Lithium‐Sulfur Batteries

Improving the slow redox kinetics of sulfur species and shuttling issues of soluble intermediates induced from the multiphase sulfur redox reactions are crucial factors for developing the next‐generation high‐energy‐density lithium‐sulfur (Li‐S) batteries. In this study, we successfully constructed a novel molecular electrocatalyst through in situ polymerization of bis(3,4‐dibromobenzene)‐18‐crown‐6 (BD18C6) with polysulfide anions on the cathode interface. The crown ether (CE)‐based polymer acts as a spatial "fence" to precisely control the unique redox characteristics of sulfur species, which could confine sulfur substance within its interior and interact with lithium polysulfides (LiPSs) to optimize the reaction barrier of sulfur species. The "fence" structure and the double‐sided Li+ penetrability of the CE molecule may also prevent the CE catalytic sites from being covered by sulfur during cycling. This new fence‐type electrocatalyst mitigates the “shuttle effect”, enhances the redox activity of sulfur species, and promotes the formation of three‐dimensional stacked lithium sulfide (Li2S) simultaneously. It thus enables lithium‐sulfur batteries to exhibit superior rate performance and cycle stability, which may also inspire development facing analogous multiphase electrochemical energy‐efficient conversion process.

Ethanediamine Intercalation Induced Hydrogen Bond Network in Vanadium Oxide for Ultralong‐Life Aqueous Ammonium Ion Batteries

Aqueous ammonium‐ion batteries (AAIBs) have received tremendous attention as a potential energy technology, but their development is severely challenged by the fact that the as‐reported electrode materials are usually unable to meet the requirements of high capacity and high stability simultaneously. Herein, an organic‐inorganic hybrid material of ethanediamine (EDA) intercalated vanadium oxide (VO‐EDA) is synthesized as a high‐performance anode material for AAIBs. The intercalated EDA molecules not only act as an electron donor to bind with NH4+, but also form hydrogen bonding network structures with vanadium oxides to facilitate charge/ion transfer. As a result, this hybrid material provides a high specific capacity of 104.4 mAh g−1 at 0.5 A g−1 and good cycling stability after 5000 cycles 10 A g−1 with a coulombic efficiency of ~100%. Moreover, the ammonium‐ion full cell based on VO‐EDA anode and NiHCF cathode achieves a specific capacity of 55 mAh g−1 at 0.1 A g−1 and impressive cycling stability with 88.6% capacity retention after 10000 cycles at 5 A g−1.

Boosting Conversion of the Si-O Bond by Introducing Fe2+ in Carbon-Coated SiOx for Superior Lithium Storage.

SiOx-based anodes are of great promise for lithium-ion batteries due to their low working potential and high specific capacity. However, several issues involving large volume expansion during the lithiation process, low intrinsic conductivity, and unsatisfactory initial Coulombic efficiency (ICE) hinder their practical application. Here, an Fe-SiOx@C composite with significantly improved lithium-storage performance was successfully synthesized by combining Fe2+ modification with a carbon coating strategy. The results of both experiments and density functional theory calculations confirm that the Fe2+ modification not only effectively achieves uniform carbon coating but also weakens the bonding energy of the Si-O bond and boosts reversible lithiation/delithiation reactions, resulting in great improvement in the electrical conductivity, ICE, and reversible specific capacity of the as-obtained Fe-SiOx@C. Together with the coated carbon, the in situ-generated conductive Fe-based intermediates also ensure the electrical contact of active components, relieve the volume expansion, and maintain the structural integrity of the electrode during cycling. And the Fe-SiOx@C (x ≈ 1.5) electrode can deliver a high-rate capacity of 354 mA h g-1 at 2.0 A g-1 and long-term cycling stability (552.4 mA h g-1 at 0.5 A g-1 even after 500 cycles). The findings here provide a facile modification strategy to improve the electrochemical lithium-storage performance of SiOx-based anodes.

Progress and Prospect of Sn‐based Metal‐organic Framework Derived Anode Materials for Metal‐ion Batteries

AbstractIn order to realize the growing demand for superior energy storage devices and electric vehicles, commercial anode candidates for next‐generation rechargeable batteries need to meet the characteristics of low cost, high energy density, high capacity, and stable performance. The emerging tin‐based anodes show great potential for high performance metal‐ion battery anodes due to their high theoretical capacity, low cost, green harmless and high safety. Tin based anode materials include tin gold based materials, tin alloy materials, tin based oxides, tin based phosphide, tin based sulfides, multi‐component composite materials, etc. However, the change in volume and structure of tin‐based anode materials during the cycle has become the biggest obstacle to its development. Metal‐organic frameworks (MOFs) provide a wide range of possibilities for achieving high rate capacity and excellent cycle stability by finely regulating the structure and composition of tin‐based materials at the molecular level. The latest progress of tin‐based materials derived from MOFs as anode materials for metal‐ion batteries (including lithium ion batteries, sodium ion batteries, potassium ion batteries, magnesium ion batteries) was reviewed in this paper. Firstly, the preparation method and morphology control of tin‐based MOF are briefly introduced, and the structural characteristics, storage mechanism and modification of tin‐based MOF derived materials are emphatically discussed. Finally, we summarized the existing modification measures and challenges of these anode materials, and put forward the prospect of the future.

Screen-Printable Iontronic Pressure Sensor with Thermal Expansion Microspheres for Pulse Monitoring.

Constructing microstructures to improve the sensitivity of flexible pressure sensors is an effective approach. However, the preparation of microstructures usually involves inverted molds or subtractive manufacturing methods, which are difficult in large-scale (e.g., in screen printing) preparation. To solve this problem, we introduced thermally expandable microspheres for screen printing to fabricate flexible sensors. Thermally expandable microspheres can be constructed into microstructures by simple heating after printing, which simplifies the microstructure fabrication step. In addition, the added microspheres can also be used as ionic liquid reservoir materials to further increase the capacitance change and improve the sensitivity. The prepared sensors exhibited superior performance, including ultrahigh sensitivity (Smax = 49999.5 kPa-1) and wide detection range (0-350 kPa). Even after 30,000 cycles at a high pressure of 300 kPa and a low pressure of 30 kPa, the sensor showed minimal signal degradation, demonstrating long-term cycling stability. In order to verify the practical potential of the sensors, we performed human radial artery beat detection experiments using these sensors. The variations in the intensity of the 3D radial artery pulse wave can be observed very clearly, which is important for human health monitoring. The above demonstrates that our strategy can provide an effective approach for the large-scale preparation of high-performance flexible pressure sensors.

Rationally Designed Li-Ag Alloy with In-Situ-Formed Solid Electrolyte Interphase for All-Solid-State Lithium Batteries.

All-solid-state lithium batteries (ASSLBs) with sulfide-based solid electrolytes have attracted significant attention as promising energy storage devices, owing to their high energy density and enhanced safety. However, the combination of a lithium metal anode and a sulfide solid electrolyte results in performance degradation, owing to lithium dendrite growth and the side reactions of lithium metal with the solid electrolyte. To address these issues, a Ag-based Li alloy with a favorable solid electrolyte interphase (SEI) was prepared using electrodeposition and applied to the ASSLB as an anode. The electrochemically formed SEI layer on the Li-Ag alloy primarily comprised LiF and Li2O with high mechanical strength and Li3N with high ionic conductivity, which suppressed the formation of lithium dendrites and short-circuiting of the cell. The symmetric cell with the Li-Ag alloy achieved a critical current density of 1.6 mA cm-2 and maintained stable cycling for over 2000 h at a current density of 0.6 mA cm-2. Consequently, the all-solid-state lithium cell assembled with the Li-Ag alloy anode with SEI, Li6PS5Cl solid electrolyte, and LiNi0.78Co0.10Mn0.12O2 cathode delivered a high discharge capacity of 185 mAh g-1 and exhibited good cycling performance in terms of cycling stability and rate capability at 25 °C.

Improved Energy Density at High Temperatures of FPE Dielectrics by Extreme Low Loading of CQDs

Electrostatic capacitors, with the advantages of high-power density, fast charging–discharging, and outstanding cyclic stability, have become important energy storage devices for modern power electronics. However, the insulation performance of the dielectrics in capacitors will significantly deteriorate under the conditions of high temperatures and electric fields, resulting in limited capacitive performance. In this paper, we report a method to improve the high-temperature energy storage performance of a polymer dielectric for capacitors by incorporating an extremely low loading of 0.5 wt% carbon quantum dots (CQDs) into a fluorene polyester (FPE) polymer. CQDs possess a high electron affinity energy, enabling them to capture migrating carriers and exhibit a unique Coulomb-blocking effect to scatter electrons, thereby restricting electron migration. As a result, the breakdown strength and energy storage properties of the CQD/FPE nanocomposites are significantly enhanced. For instance, the energy density of 0.5 wt% CQD/FPE nanocomposites at room temperature, with an efficiency (η) exceeding 90%, reached 9.6 J/cm3. At the discharge energy density of 0.5 wt%, the CQD/FPE nanocomposites remained at 4.53 J/cm3 with an efficiency (η) exceeding 90% at 150 °C, which surpasses lots of reported results.