Solid-state Batteries Research Articles

Rhombohedral Li1-xZr2-xSbx(PO4)3 electrolytes with improved Li+ conductivity for high-performance solid-state Li-metal battery

Recent studies on solid electrolytes have promoted the development of solid-state Li-metal batteries (SSLBs). The NASICON-type LiZr2(PO4)3 (LZP) electrolyte has received less attention due to its low conductivity and the existence of several crystal forms, which have impeded the development of LZP-based materials for SSLBs. Herein, Li1-xZr2-xSbx(PO4)3 (LZSP) ceramics were synthesized by solid-state method, and the cycle performances of symmetrical cell and Li-metal battery using LZSP electrolyte were characterized for the first time. The Sb5+ doping stabilizes the rhombohedral phase at room temperature and results in distortions in the ZrO6 octahedron and PO4 tetrahedron, which lead to variations of bond length and bond angle. The room temperature total conductivity of Li0.94Zr1.94Sb0.06(PO4)3 (LZSP-0.06) increased to 6.53 × 10−5 S·cm−1. This rise can be attributed to a reduction of the Li+ ions transport barrier originated from variations of bond length, bond angle and Raman vibrations mode. The Li/LZSP-0.06/Li symmetrical cell maintains a stable cycle duration of 670 h at a current density of 0.12 mA cm−2. The specific capacity of Li/LZSP-0.06/LiFePO4 battery reaches 140.1 mAh g−1 at 0.5C and the coulombic efficiency is 99.8 %. This battery maintains 80 % capacity after 105 cycles. These results provide reference significance for the research on SSLBs using LZP-based electrolytes. In general, the Li0.94Zr1.94Sb0.06(PO4)3 ceramic appears to be a promising solid electrolyte for SSLBs.

Enhancement in conductivity by K2O in MgO-V2O5 glass-ceramic for solid- state battery application

Composition of 75V2O5-(25-x) MgO-(x) K2O (x = 6, 9, 12, and 15 mol%) are synthesized by melt quench technique. All the as quenched samples either formed the glasses or glass ceramic as confirmed by differential scanning calorimeter (DSC) and X-ray diffraction (XRD). The DSC curves exhibited the two glass transition temperatures (Tg), two crystallization temperatures (Tc), and with two melting temperatures (Tm) which could be related to the presence of two distinct glass in the present samples. The K2O content increases the devitrification tendency of as quenched samples and formed the crystalline phases i.e. K3VO4 along with glassy phase in higher concentration of K2O. X-ray photoelectron spectroscopy (XPS) is confirmed that the vanadium exhibit two oxidation states V4+ / V5+. The highest ratio of V4+/V5+ is found in (x = 15) sample which exhibited the highest conductivity i.e. 1.3 × 10−3 S/cm at 250 °C. It is two orders higher than the (x = 6) sample at 250 °C. The high conducting glass ceramics can be used as cathode in all solid state battery and fuel cells.

Cu-doped Fe3O4 supported on porous NC-coated carbon cloth for robust flexible nickel–iron batteries

The pursuit of safe, cost-efficient, environment-friendly and portable energy storage devices has greatly stimulated the exploitation of aqueous flexible batteries that are green and stable. Ni-Fe aqueous batteries have become an ideal choice for flexible energy storage devices due to the advantages such as large theoretical capacity, good safety and low cost. In this work, Fe3O4 is chosen as the active material for the anode of Ni-Fe batteries, which is grown on a modified carbon cloth of PNC/CC with a coating layer of porous nitrogen-carbon. The PNC/CC, as a flexible current collector, has higher hydrophilicity, porosity and conductivity. To further improve the electronic conductivity, ionic adsorption ability, morphology and capacity of the Fe3O4 anode, Cu2+ is added during Fe3O4 growth, which not only brings more homogeneous and full coverage of spherical Cu/Fe3O4 particles on PNC/CC, but also greatly lowers its electrode–electrolyte charge transfer resistivity, increases its ionic diffusion and accelerates its redox reaction activity. With optimized electrochemical reactions, the Cu/Fe3O4@PNC/CC anode shows a much higher capacity of 170.7 mAh/g than bare Fe3O4/CC anode (1 A/g). Solid-state aqueous Ni-Fe batteries are assembled using the Cu/Fe3O4@PNC/CC anode and a NiCoLDH cathode, exhibiting a capacity of 88.56 mAh/g at 1 A/g, capacity retention of 88.19 % during 2000 cycles, as well as the energy density reaching 96.6 Wh kg−1 and the power density reaching 9.7 kW kg−1. Moreover, flexible Ni-Fe battery devices are also fabricated, which can maintain relatively stable electrochemical performance at various bending angles and low temperatures. This works brings some insights for the synthesis and modification of Fe3O4-based anodes for flexible and solid-state Ni-Fe batteries.

Estimation of state of charge for polymer solid-state batteries: Ensemble learning models and temperature impact study

In addition to the research and development of solid electrolytes to improve battery performance, an efficient battery management system (BMS) is a must to ensure safe use and extend battery life, and state of charge (SOC) estimation is critical in the BMS. This paper presents a novel temperature-influenced method for estimating the SOC of polymer-based solid-state batteries in real-time, using machine learning to capture the relationship between SOC and battery characteristics at different temperatures. The results show that accurate SOC estimation results can be achieved at different temperatures, with an average root mean square error of 1.42 %. Furthermore, the method uses Shapley Additive explanation (SHAP) to reduce the degree of black box nature of the model and analyzes the electrochemical processes inside the battery at different temperatures through relaxation time distribution. Accurate estimates of SOC and guidelines for appropriate operating temperatures can serve as a basis for BMS decision-making and improve the lifetime of polymer-based solid-state batteries.

Solid polymer electrolytes with dual salts enhance lithium-metal interfacial stability for long cycle performance of lithium batteries

Solid-state lithium metal batteries (LMBs) are considered to be the ideal energy storage system for achieving higher energy density and high safety. However, poor physical contact at the interface between the solid-state electrolyte and lithium metal, as well as the growth of dendrites make the cycling stability of LMBs challenging. Therefore, we developed a multifunctional ionic liquid-based polymer electrolyte including montmorillonite (MMT) and double salts (NaFSI and LiTFSI). The self-concentration effect of MMT lithium ions, combined with the electrostatic shielding effect of the double salts, resulted in homogeneous ion deposition, reducing dendritic lithium generation and improving lithium battery performance, with lithium batteries achieving a stable cycling rate of 1000 cycles at 1 C. Moreover, Due to the integrated assembly of the battery assembly process using light curing, the physical interface between the positive electrode-electrolyte-negative electrode achieves good contact and wettability. NaFSI achieves the enhancement of solid electrolyte interface (SEI) by introducing NaF/LiF to SEI of lithium metal, and the optimization of ion deposition pattern at the interface can be achieved by electrostatic shielding effect. Ultimately, stable ion transport at the solid-solid interface for lithium metal solid-state batteries can be realized. Notably, the ionic liquid-based polymer electrolyte with high ionic conductivity (1.2 × 10−3 S cm−1) and high oxidative stability (5.2 V vs. Li/Li+) at room temperature. In addition, the good flame retardant properties of the electrolytes indicate that dual-salt polymer electrolytes are an effective strategy for achieving high safety and long cycle stability of LMBs.

Constructing Donor–Acceptor-Linked COFs Electrolytes to Regulate Electron Density and Accelerate the Li+ Migration in Quasi-Solid-State Battery

HighlightsDonor–acceptor-linked covalent organic framework (COF)-based electrolyte can not only fulfill highly-selective Li+ conduction, but also offer a crucial opportunity to understand the role of electronic density in quasi-solid-state Li metal batteries.Donor–acceptor-linked COF electrolyte results in Li+ transference number 0.83, high ionic conductivity 6.7 × 10–4 S cm−1 and excellent cyclic ability in Li metal batteries.In situ characterizations, density functional theory calculation and time-of-flight secondary ion mass spectrometry are adopted to expound the mechanism of the rapid migration of Li+ in the “donor–acceptor” electrolyte system.

Compositional Engineering of Lithium Metal Anode for High-Performance Garnet-Type Solid-State Lithium Battery.

Garnet-type solid-state lithium batteries (SSLBs) possess excellent potential owing to their safety and high energy density. However, fundamental barriers are deficient cycling stability and poor rate capability. The main concern lies in generating voids at the Li|garnet interface during Li stripping, stemming from the sluggish diffusion of Li atoms inside the bulk Li metal. Herein, a composite anode (AN@Li) containing Li-Al alloy, Li3N, and LiNO2 is designed by introducing aluminum nitrate into molten Li. The lower interfacial formation energies exhibited by Li-Al alloy, Li3N, and LiNO2 with garnet solid-state electrolyte (SSE) enhance the wettability of AN@Li toward SSE. Meanwhile, it affords efficient conductive pathways that facilitate Li+ diffusion in the bulk anode (not just on the surface). Impressively, the resulting symmetric cell with AN@Li electrodes achieves high critical current density (1.95mA cm-2) and long cycle life (6000h at 0.3mA cm-2). The SSLB coupled with LiFePO4 cathode and AN@Li anode enables stable cycling for 200 cycles at a high rate of 1 C with a retention of 96% and exhibiting outstanding rate capability (145.9 mAh g-1 at 2 C). This work provides practical insights for producing high-performance lithium metal anode for advanced garnet-type SSLBs.

Evaluation of Oxide|Sulfide Heteroionic Interface Stability for Developing Solid-State Batteries with a Lithium-Metal Electrode: The Case of LLZO|Li6PS5Cl and LLZO|Li7P3S11.

Developing solid-state batteries (SSB) with a lithium metal electrode (LME) using only one type of solid electrolyte (SE) is a significant challenge since no SE fits all the requirements imposed by both electrodes. A possible solution is using multilayer SSBs with an LME where the drawbacks of each SE are overcome by using layers of different SEs. However, research on inorganic SE1|SE2 heteroionic interfaces is still quite preliminary, especially regarding oxide|sulfide heteroionic interfaces. This work reports the electrochemical investigation of the heteroionic interface between Li6.25Al0.25La3Zr2O12 (Al-LLZO) and two representative materials for sulfide-based SEs: argyrodite-based Li6PS5Cl (LPSCl) and glass-like Li7P3S11 (LPS711). Through in-depth temperature- and pressure-dependent impedance analyses of multilayer symmetric cells at equilibrium (i.e., no current load), the electrical properties of the heteroionic interfaces are assessed. The pressure-dependent kinetic of the Al-LLZO|LPSCl pair is interpreted with the concept of geometric constriction resistance and show that its resistance is lower than for the Al-LLZO|LPS711 pair. Furthermore, the effect of Al-LLZO surface treatment on the electrical properties of the Al-LLZO|LPSCl heteroionic interface is evaluated. Such investigation shows that the value of the interface activation energy decreases when the Al-LLZO surface is heat treated, revealing a significant influence of the carbonate/hydroxide passivation layer on the heteroionic interface. Additionally, by cycling the symmetric cell for 900 h at 1.0 mAh·cm-2, it is revealed that the Al-LLZO|LPSCl interface has a lower impedance increase than the Al-LLZO|LPS711 interface, especially if the Al-LLZO is heat treated. With this work, we highlight that the oxide|argyrodite combination can be a promising candidate for multilayer SSBs with an LME. However, we show that an optimized LLZO surface treatment and chemical analysis of the interface are recommended for future research.

Imaging the microstructure of lithium and sodium metal in anode-free solid-state batteries using electron backscatter diffraction.

'Anode-free' or, more fittingly, metal reservoir-free cells could drastically improve current solid-state battery technology by achieving higher energy density, improving safety and simplifying manufacturing. Various strategies have been reported so far to control the morphology of electrodeposited alkali metal films to be homogeneous and dense, but until now, the microstructure of electrodeposited alkali metal is unknown, and a suitable characterization route is yet to be identified. Here we establish a reproducible protocol for characterizing the size and orientation of metal grains in differently processed lithium and sodium samples by a combination of focused ion beam and electron backscatter diffraction. Electrodeposited films at Cu|Li6.5Ta0.5La3Zr1.5O12, steel|Li6PS5Cl and Al|Na3.4Zr2Si2.4P0.6O12 interfaces were characterized. The analyses show large grain sizes (>100 µm) within these films and a preferential orientation of grain boundaries. Furthermore, metal growth and dissolution were investigated using in situ electron backscatter diffraction, showing a dynamic grain coarsening during electrodeposition and pore formation within grains during dissolution. Our methodology and results deepen the research field for the improvement of solid-state battery performance through a characterization of the alkali metal microstructure.

Enhancing the electrochemical properties of polyethylene oxide solid-state electrolytes based on a small nano-sized UiO-66 metal-organic framework

Metal-organic frameworks (MOFs) have garnered significant attention in the field of Lithium-ion batteries due to their porous periodic network properties. However, this is a challenge to design high-performance solid-state electrolytes reasonably. Herein, a small nano-sized MOF Small-UiO-66 is reported, which has high surface area and mesoporous properties that can effectively inhibit PEO matrix crystallization. The presence of Small-UiO-66 accelerates the dissociation of lithium salts, which disrupts the ordered arrangement of the PEO chain segments. The abundant Lewis acidic sites on the surface of Small-UiO-66 facilitate the construction of abundant Li+ transport channels and promote Li+ conduction. Furthermore, the smaller nano-sized increase the interfacial wettability with lithium metal, which promotes the uniform diffusion of Li+ and inhibits the growth of lithium dendrites. The results indicate that 0.1 Zr-CSE exhibits high ionic conductivities of 6.94 × 10−4 S/cm at 60 °C. Based on 0.1 Zr-CSE, the Li||Li symmetric cell can operate stably for 1200 h at a current density of 0.1 mA/cm2, and the LFP||Li cell also achieves a high initial capacity of 147.65 mAh·g−1 at current densities of 0.5C. This work presents a novel approach for preparing high-performance solid-state Lithium-ion batteries using MOFs as fillers for polymer solid-state electrolytes.

Tuning collective anion motion enables superionic conductivity in solid-state halide electrolytes.

Halides of the family Li3MX6 (M = Y, In, Sc and so on, X = halogen) are emerging solid electrolyte materials for all-solid-state Li-ion batteries. They show greater chemical stability and wider electrochemical stability windows than existing sulfide solid electrolytes, but have lower room-temperature ionic conductivities. Here we report the discovery that the superionic transition in Li3YCl6 is triggered by the collective motion of anions, as evidenced by synchrotron X-ray and neutron scattering characterizations and ab initio molecular dynamics simulations. Based on this finding, we used a rational design strategy to lower the transition temperature and thus improve the room-temperature ionic conductivity of this family of compounds. We accordingly synthesized Li3YClxBr6-x and Li3GdCl3Br3 and achieved very high room-temperature conductivities of 6.1 and 11 mS cm-1 for Li3YCl4.5Br1.5 and Li3GdCl3Br3, respectively. These findings open new routes to the design of room-temperature superionic conductors for high-performance solid batteries.

Enhancing composite cathode manufacturing with machine learning for polymer electrolyte solid-state batteries

Solid-state batteries (SSBs) represent a pivotal advancement in battery technology, poised to surpass lithium-ion batteries and drive the electrification of mobility. However, achieving cost-effective, scalable, and sustainable fabrication processes for SSB components remains a challenge. This study integrates machine learning (ML) techniques to optimize manufacturing processes of cathodes for polymer electrolyte based SSBs. The findings reveal strong predictive performance of regression models for active material loading, with support vector machine emerging as the top performer. Multiclassification models exhibit satisfactory precision, particularly in categorizing ideal electrode samples. Analysis of principal component and correlation circles highlight viscosity and wet thickness as critical variables for mixing and coating, respectively. Despite promising metrics, dataset imbalance and size limit model robustness. Further dataset augmentation is recommended before deployment in production. ML techniques offer promise in advancing battery manufacturing, paving the way for enhanced SSB performance and broader application across battery components.

Durable high voltage solid-state sodium batteries with Pseudocapacitive P2 layered oxide cathode

Solid-state sodium batteries (SSBs) have attracted great interests due to their high energy density, good safety and low cost, but their performance including operation voltage, cycling stability and rate capability are far from satisfactory. In this study, a P2-Na0.68Li0.10Ni0.25Mn0.63Ca0.01Ti0.01O2 (NM-L10CT) layered cathode material were successfully fabricated, which possesses a high pseudocapacitance over 92 %, low volume strain of 0.8 %, high Na-ion diffusion coefficient and very good reversibility of anionic redox reaction. Moreover, room temperature solid-state sodium batteries with NM-L10CT and Na3Zr2Si2PO12 (NZSP) solid electrolyte are demonstrated, displaying much improved structural stability and cycling performance compared with that in liquid electrolyte batteries. The NM-L10CT/NZSP/Na SSBs exhibit very excellent electrochemical performance under high cut-off voltage, with high retention rates of 81.2 % after 500 cycles (2.0–4.2 V) and 74.2 % after 300 cycles (2.0–4.3 V), respectively. It has an outstanding rate performance with a high capacity of 115.4 mAh g-1 at 1 C and 74.5 mAh g-1 even at 10 C rate. This is due to the significantly reduced interface resistance and improved structural stability in solid state. This work demonstrates the successful application of high voltage layered cathode in SSBs and provides the insightful understanding of such material in liquid electrolyte and solid state battery.

Ga-ion migration during co-sintering of heterogeneous Ta- and Ga-substituted LLZO solid-state electrolytes

Li7La3Zr2O12 (LLZO) is an attractive solid-state electrolyte for next-generation lithium solid-state batteries (SSB) because of its high ionic conductivity, and safety properties. Only the cubic LLZO phase has sufficient ionic conductivity, which is stabilized by substitution with elements like Ta or Ga. Ga-substituted LLZO has the highest ionic conductivity but is not stable towards metallic Li anodes, while Ta-substituted LLZO has a slightly lower conductivity but excellent reduction stability towards Li anodes. The combination of LLZO:Ga as a catholyte and LLZO:Ta as a ceramic separator for Li anodes would significantly enhance the performance of SSBs, but both materials have different processing parameters. In this work, the possibility of co-sintering LLZO:Ga|LLZO:Ta components is investigated with varying Li-excess of the LLZO:Ta phase, while the results are compared with pure references. The experiments showed a changed sintering activity, secondary phase formation, Ta- and Ga-ion diffusion, and a changed ionic conductivity when co-sintering LLZO:Ga|LLZO:Ta.

Direct Precursor Route for the Fabrication of LLZO Composite Cathodes for Solid-State Batteries.

Solid-state batteries based on Li7La3Zr2O12 (LLZO) garnet electrolyte are a robust and safe alternative to conventional lithium-ion batteries. However, the large-scale implementation of ceramic composite cathodes is still challenging due to a complex multistep manufacturing process. A new one-step route for the direct synthesis of LLZO during the manufacturing of LLZO/LiCoO2 (LCO) composite cathodes based on cheap precursors and utilizing the industrially established tape casting process is presented. It is shown that Al, Ta:LLZO can be formed directly in the presence of LCO from metal oxide precursors (LiOH, La2O3, ZrO2, Al2O3, and Ta2O5) by heating to 1050°C, eliminating the time- and energy-consuming synthesis of preformed LLZO powders. In addition, performance-optimized gradient microstructures can be produced by sequential casting of slurries with different compositions, resulting in dense and flat phase-pure cathodes without unwanted ion interdiffusion or secondary phase formation. Freestanding cathodes with a thickness of 85µm, a relative density of 95%, and an industrial relevant LCO loading of 15mg show an initial capacity of 82 mAh g-1 (63% of the theoretical capacity of LCO) in a solid-state cell with Li metal anodes, which is comparable to conventional LCO/LLZO cathodes and can be further improved in the future.

Lithium-rich high entropy oxide with abundant oxygen vacancies for composite polymer all-solid-state Li-S batteries

Poly(ethylene-oxide) (PEO)-based all-solid-state lithium-sulfur (Li-S) batteries simultaneously possess the advantage of extraordinary theoretical energy density and high safety, high machinability. However, the challenges of lithium polysulfide (LiPS) shuttling and insufficient Li+ conductivity hinder the batteries from practical application. In this work, a lithium-rich high entropy oxide with abundant oxygen vacancies (HL30) is developed as an active filler in PEO to concurrently address the two issues. Specifically, the addition of HL30 promotes the mobility of Li+ in PEO electrolyte as well as provides an extra high-efficiency pathway for Li+ transport, leading to large enhancement of the Li+ ionic conductivity. The metal species in HL30 could anchor the LiPS via bonding interaction while the surface oxygen vacancies further increase the bonding energy. As a result, the ionic conductivity of HL30-containing electrolyte reaches 5.06 × 10−4 S cm−1 at 60 °C, exceeding that of pure PEO electrolyte (2.45 × 10−4 S cm−1) to a considerable extent. The coulombic efficiency of Li-S full battery decreases from 113 % to 103 %, revealing an efficient restriction of shuttling effect. This work provides a novel method of composite polymer electrolyte design to achieve the practical application of high-performance solid-state Li-S batteries.

Heterostructured fluoride-based solid electrolytes engineered by grain boundary softening and bonding for sustainable Na metal batteries

Fluoride solid electrolytes stand out as promising candidates for high-energy-density solid-state batteries owing to their inherent structural and air stability. However, their application in sodium based batteries has been hindered by their low ionic conductivity. Here, we propose a heterostructured fluoride-based solid electrolyte engineered by grain boundary softening and bonding for sustainable Na metal batteries. By leveraging a low-melting-point chloride eutectic mixture NaCl-1.1AlCl3 (NA), we achieve the in situ activation of sodium ion transport at the grain boundaries of Na3GaF6 (NGF), with the formation of a molten salt interphase primarily composed of NaAlCl4. This process effectively softens the edges of NGF and heals the intergranular voids. The NA decorated NGF electrolyte exhibits the significantly enhanced ionic conductivities of 2.7 × 10–4 S/cm at 60 °C and 2.45 × 10–5 S/cm at room temperature, representing two orders of magnitude improvement over pure NGF. The chloride shell does not degrade the wide electrochemical window and air stability of NGF. This electrolyte relies on a unique "self-protection" mechanism when cycling with sodium metal anode. The molten salt phase can evolve into a compact NaCl protective shell and an Na-Al conductive inner layer with tight contact with Na anode. This dual-layer structure mitigates the side reaction with NGF host, homogenizes the current flow, and suppresses the growth of sodium dendrites. The corresponding Na//Na symmetric cells display the small voltage polarization and stable cycling performance for over 1000 h. The solid-state Na//FeF3 batteries deliver a high capacity of 308 mAh/g and sustain for at least 100 cycles with high capacity retention based on conversion reaction.

Energy transition in the new era: The impact of renewable electric power on the life cycle assessment of automotive power batteries

Amid escalating global concern for environmental issues, the advancement and utilization of renewable energy take on unprecedented importance. This study focuses on the field of electric vehicle power batteries. Through constructing a life cycle assessment model, integrating various types of renewable electrical energy and various battery recovery analysis scenarios, we explored the carbon footprint and environmental impact of Nickel-Cobalt-Manganese (NCM), Lithium Iron Phosphate (LFP), All Solid State Nickel-Cobalt-Manganese (A-NCM), and All Solid State Lithium Iron Phosphate (A-LFP) batteries in the context of China. The research reveals that using renewable electrical energy could reduce carbon emissions by 50%–70 % compared to traditional energy, while also significantly enhancing other environmental performance metrics, notably with hydropower. Solid-state batteries have a more substantial environmental impact during the production phase, approximately 27 % higher than similar lithium batteries, with NCM outpacing LFP. However, in the usage phase, NCM batteries, due to their unique structure, significantly mitigate energy losses compared to LFP batteries. The study also found that hydrometallurgical recycling had superior efficiency and environmental benefits in the recycling stage. Providing a scientific foundation for sustainable policies, this study promotes the enhancement of energy structures and battery recovery in the automotive industry.

Interplay of Interfacial Adhesion and Mechanical Degradation in Anode-Free Solid-State Batteries

Abstract Anode-free solid-state batteries (AFSSBs) with an Ag-C interlayer are an innovative architecture because of their high energy density compared to conventional Li metal solid-state batteries. This work introduces simple methods to enhance the interfacial adhesion strength between the Ag-C interlayer and the solid electrolyte (SE) for better initial capacity of the cell, by controlling the cell assembling pressure to place together all components of the cell. Through contact angle experiments, our study unveils how the variation in the assembling pressure can significantly influence the contact angle between SE (at different assembling pressures) and Li metal, affecting their adhesion energy. Our electrochemical tests evidence that raising the assembling pressure from 350MPa to 530MPa outcomes an increment of more than 50% in initial capacity due to higher adhesion energies, with the corresponding energy density of 410 Wh/kg. Nonetheless, SE separator tends to crack beyond a critical assembling pressure of 530MPa that might cause a dramatic decrease of the cell performance. Our findings show that increasing the interfacial adhesion through different methods can prevent interface degradation and increase energy density of AFSSBs, affirming the vital role of interfacial adhesion between the Ag-C interlayer and SE separators, holding significant advances in anode free architectures.

Porous structural battery composite for coordinated integration of mechanical and electrical functionalities

AbstractStructural battery composites (SBCs) represent an emerging multifunctional technology in which materials functionalized with energy storage capabilities are used to build load‐bearing structural components. However, due to the liquid electrolyte contamination in structural battery electrolyte (SBE) and the large volume expansion of active battery materials, the poor interlayer interfacial in multilayer SBCs often causes difficulties in practical use. In this study, a new porous LiFePO4‐graphite SBC is designed and fabricated by independently distributing battery materials and resin matrix on carbon fiber fabric in pattern lattice form to prepare electrodes prepreg. The cured porous composite framework supports the load‐bearing function while limiting the electrochemical reaction in liquid electrolyte within lattices. The electrodes show reversible electric resistance after 3000 bending cycles with radius as small as 10 mm. The mechanical properties enhance significantly with tensile strength of 486.1 MPa and Young's modulus of 9.1 GPa compared to that with a liquid–solid biphasic mixed SBE structure. The SBC also exhibits a favorable capacity of 27.8 mAh/g at 0.1C. This straightforward integration path of mechanical and electrical functionalities is compatible with the manufacturing process of aerospace composite structures, which will provide an efficient and convenient energy supply solution for distributed electronics.Highlights A porous full‐cell structural battery composite (SBC) was designed and fabricated with prepregs. A suspension deposition and volatilization method was developed for robust battery material coating. Electrodes layer exhibited reversible electric resistance after 3000 tensile/bending cycles. The tensile strength and modulus increased significantly compared to the SBC with liquid–solid biphasic mixed structural battery electrolyte. Coordinated integration path was completely compatible with the manufacturing process of aerospace composite structures.