Excellent Electromagnetic Interference Research Articles

High-Performance Flexible Pressure Sensor with Micropyramid Structure for Human Motion Signal Detection and Electromagnetic Interference Shielding.

Flexible pressure sensors have a wide range of applications in the field of human motion signal detection, but the electromagnetic radiation generated during the monitoring process has become an unavoidable problem. Nowadays, it is still a challenge to develop high-performance pressure sensors with excellent electromagnetic interference (EMI) shielding performance. Herein, the Ti3C2TX MXene/carbon fiber/multiwalled carbon nanotube/polydimethylsiloxane (MXene/CMP) films with a micropyramidal structure were developed by the technology of vacuum high-temperature hot pressing and spray deposition. Benefiting from the dielectric loss of the conductive fillers and the presence of the microstructure, the MXene/CMP film exhibits excellent EMI shielding performance, and the EMI shielding efficiency (SE) can reach 49.37 dB. Besides, the introduction of CF effectively improves the mechanical properties of the MXene/CMP films, and the MXene nanosheets deposited on the surface of the film can reduce stress concentration, which in turn delays the expansion of cracks. Furthermore, the MXene/CMP sensor exhibits high sensitivity (89.76 kPa-1) and fast response/recovery time (61/60 ms). The deformation of microstructure and the construction of conductive networks enable the sensor to realize the monitoring of human motion signals (such as finger bending, knee bending, wrist bending, etc.). Meanwhile, the sensor maintains sensing stability even after 2000 pressure cycles, which can be attributed to the improvement in mechanical properties. In summary, the developed high-performance flexible pressure sensor with micropyramid structure has great application prospects in wearable devices and healthcare.

Yarn-Based Degradable Janus PPDO Fabric for Multifunctional Applications.

The growing high standard of people's wear has put forward requirements for fabrics, and multifunctional fabrics have been developed precisely in response to the requirements of the times. However, the incineration of waste fabrics produces a large amount of pollutants, resulting in a massive waste of resources and environmental pollution. Herein, the degradable nanofiber yarns (NYs) with self-cleaning properties were fabricated by in situ growth of SiO2 nanoparticles on the surface of the electrospun poly(p-dioxanone) (PPDO) NYs using the Stöber method. Then, the PPDO NYs were blended with carbon fibers and the PPDO/SiO2 NYs with themselves to form the Janus PPDO fabrics, respectively. The Janus PPDO fabric offered asymmetric wettability and dual personal thermal management properties. The PPDO/C side of the Janus PPDO fabric provided 65.8 °C at 1.5 V or 58.5 °C under one sunlight intensity for radiative heating. The PPDO/SiO2 side exhibited high solar reflectivity (81.8%) and mid-infrared (MIR) emissivity (99.1%), which reduced the skin temperature by 4.6 °C, resulting in radiative cooling. Moreover, the Janus PPDO fabrics display an excellent electromagnetic interference (EMI) shielding performance (53.3 dB). Therefore, yarn-based degradable Janus fabric has a promising future in multifunctional wearable products.

Preparation and Characterization of Lightweight Carbon Foam Derived From Silicon‐Containing Arylacetylene Resin With Antioxidant Properties and Excellent Electromagnetic Interference Shielding Performance

ABSTRACTIn this study, carbon foam derived from silicon‐containing arylacetylene resin (CFPSA) was prepared by using silicon‐containing arylacetylene (PSA) resin as the carbon precursor and polyurethane (PU) foam as the organic sacrificial template. CFPSAs with diverse apparent densities were prepared through the simple impregnation of PU foam with PSA resin solutions of varying concentrations. Their structures, such as the pore morphology; chemical composition; thermal stability; compression properties, and electromagnetic interference (EMI) shielding effectiveness (SE), were characterized. The results indicate that with an increase in the PSA resin concentration, the skeleton of CFPSA becomes thicker, the pore size slightly increases, the apparent density increases, the compressive strength increases, and the EMI SE slightly reduces. CFPSA‐10's apparent density is 0.032 g/cm3, its 5% thermal weight loss temperature (Td5) in an air atmosphere is 642°C, its thermal conductivity is 38.1 mW/m K, its specific compression strength is 2.45 MPa/g cm3, and its specific EMI SE divided by thickness (SSE/t) is 2367 dB cm2/g. CFPSA exhibits lightweight and antioxidant properties, as well as excellent electromagnetic interference shielding performance, presenting great potential for application in aerospace and other fields.

Epoxy microlattice with simultaneous self-sensing and electromagnetic interference shielding performance by in-situ additive manufacturing

The development of epoxy nanocomposite architectures capable of self-sensing the internal structural response to mechanical stimuli and exhibiting multifunctionality represents a significant challenge to the scientific community. Here, an in-situ additive manufacturing technique is developed to construct robust SiO2/epoxy host material and piezoresistive nanocarbon/epoxy sensing elements into an engineered 3D microlattice. The integration of microscale sensing elements with tailored embedment locations and contents enables the real-time detection of in-situ strain under varying loadings, without compromising the mechanical properties of the original host structure. Additionally, the epoxy microlattices containing 3D interconnected network of sensing elements present excellent electromagnetic interference shielding properties, attaining a high shielding effectiveness of up to 33 dB. Furthermore, the applications of the epoxy microlattice in defect-recognizable composite lattices and multifunctional protective devices are demonstrated. The present findings suggest an effective strategy for the development of intrinsically smart epoxy nanocomposites with customized microstructure and unprecedented multifunctionality.

Flexible, transparent, and low-temperature usable electromagnetic shielding film based on orthogonally arranged silver nanowire network/graphene oxide conductive network

With the increasing diversification of application environments of new electronic products, demands are being placed on flexibility, transparency, and stable operation capability even under harsh conditions of electromagnetic shielding films. Aiming at the issue of high contact resistance of simple silver nanowire (AgNWs) conducting network, this work utilizes orthogonally arranged AgNWs and graphene oxide (GO) to establish unique AgNWs/GO conductive network, achieving more conductive nodes and enhancing the stability of the conductive network. The resulting AgNWs/GO film exhibits a reduced resistance of 9.8 Ω/sq, an impressive light transmittance of 85.7 % (λ = 550 nm), and excellent electromagnetic interference shielding efficiency (EMI SE) reaching 30.3 dB in the X-band (8.2–12.4 GHz). Moreover, the AgNWs/GO film exhibits the potential for long-term operation in harsh environments. After undergoing numerous bending cycles (10,000 times), prolonged exposure (90 days), and repeated energization (800 times), the resistance of the AgNWs/GO film remains extremely stable. Furthermore, the film demonstrates remarkable electrothermal conversion capability in cold environments, rapidly heating to 73.3 ℃ under a 4 V voltage and maintaining stability thereafter. After 800 h of operation, there is negligible change in its electrothermal properties. The development of such a flexible electromagnetic shielding film holds significant implications for various applications.

Silver nanoparticles bridging liquid metal for wearable electromagnetic interference fabric

Stretchable conductive fibers are essential for the advancement of wearable electronic textiles. However, a significant challenge arises as their conductivity sharply decreases when stretched due to disruptions in electronic transport. Coating fibers with soft liquid metal (LM) has emerged as a promising solution. Despite this, there remains an urgent need to develop methods that enhance LM adhesion to substrates while facilitating efficient electron transport pathways. This study demonstrates a novel Ag-LM conductive network strategy for fabricating a thermoplastic polyurethane/polydopamine/silver-LM (TPU/PDA/Ag-LM) fiber membrane. This membrane exhibits outstanding stretchable electromagnetic interference (EMI) shielding performance and is produced through straightforward electrospinning, electroless depositing, and LM coating and activation. The TPU/PDA/Ag fiber membrane is initially prepared via polydopamine-assisted deposition of silver nanoparticles (AgNPs) on electrospun TPU fibers. The presence of AgNPs on the surface of TPU/PDA fibers enhances LM adhesion to the substrate and bridges adjacent LM to establish efficient conductive paths. This interaction benefits from the reactive alloying between AgNPs and LM, where the LM infiltrates the gaps among AgNPs, forming a distinctive LM-Ag alloy layer that uniformly coats the surface of TPU fibers. As anticipated, the unique three-dimensional (3D) interconnected LM-Ag conductive network remains intact during stretching, ensuring strain-invariant conductivity. The fabricated TPU/PDA/Ag-LM fiber membrane demonstrates exceptional EMI shielding effectiveness (SE) of 77.4 dB within the frequency range of 8.2–12.8 GHz and maintains an excellent EMI SE of 37.2 dB under extensive tensile deformation of 300%. Furthermore, the TPU/PDA/Ag-LM fiber membrane shows remarkable mechanical properties and stable Joule heating performance even under significant stretching.

Interfacial enhancement enables highly conductive reduced graphene oxide-based yarns for efficient electromagnetic interference shielding and thermal regulation

Although the coating of conductive graphene onto commercial yarns is promising for scalable production, the resulting conductive yarns are susceptible to the coating detachment, causing reduced conductivity and poor stability. Herein, we propose a scalable and cost-effective interfacial enhancement strategy for fabricating highly conductive yarns with satisfactory mechanical properties by modifying polyamide yarns with polyethyleneimine to enhance their interaction with graphene oxide (GO) sheets and subsequently reducing the GO component with hydroiodic acid. Because the enhanced interfacial interactions of the polyethyleneimine-modified polyamide yarns with the GO sheets improve the loading of GO and the coating stability, the resultant yarns can withstand bending, embroidering, sewing and weaving, maintaining an extraordinary conductivity of 4.7 × 103 S m−1 after 10000-cycle bending. The conductive textiles woven by the yarns reach an excellent electromagnetic interference (EMI) shielding effectiveness of 66.7 dB at the thickness of 0.615 mm along with superior hydrophobicity, satisfactory air permeability, and high electrothermal and solar-thermal energy conversion performances. The EMI shielding effectiveness of the textile is well maintained even after 5000-cycle bending, demonstrating its satisfactory stability. This work demonstrates an interfacial enhancement strategy for the large-scale fabrication of multifunctional yarns that hold great promise for EMI shielding, personal thermal regulation, and deicing applications.

Effect of La content on mechanical properties and electromagnetic interference shielding effectiveness of Mg-Zn-Y-La-Zr alloy

In recent years, a great demand exists for Mg alloy materials that combine excellent mechanical properties and electromagnetic interference shielding effectiveness (EMI SE). In this study, the effects of La content on the microstructure, mechanical properties, and EMI SE of Mg-6Zn-1Y-xLa-0.5Zr alloys are reported in detail. The microstructures of Mg-6Zn-1Y-xLa-0.5Zr alloys treated by extrusion all exhibit bimodal microstructure characteristics. Mg-6Zn-1Y-1.0La-0.5Zr alloys show a superior balance between mechanical properties and EMI SE. The UTS, YS, and elongation were 332.3 MPa, 267.3 MPa, and 16.2 %, respectively. Meanwhile, the EMI SE in the frequency range of 30–1500 MHz is 79–110 dB, and the excellent mechanical properties are due to the combined effect of fine-grain strengthening, second-phase strengthening, and heterogeneous structure strengthening. The excellent EMI SE is mainly attributed to the dense and diffusely distributed second phase providing more interfaces that can reflect electromagnetic waves.

Bi-functional flexible Ag2Se/Polyvinylidene fluoride composite films for thermal energy conversion and electromagnetic interference shielding by solution 3D printing

Developing bi-functional thermoelectric (TE) and electromagnetic interference (EMI) shielding materials is an effective way for the integrated electronic devices to face the accumulated thermal energy and complicated electromagnetic environment. Herein, flexible Ag2Se/polyvinylidene fluoride (Ag2Se/PVDF) composite films were successfully prepared through solution 3D printing and subsequent annealing treatment. As Ag2Se content increased, both the power factor and average total EMI shielding effectiveness (SET) were boosted. When the mass fraction of Ag2Se was 85 wt%, a power factor of 904.6 μW m−1K−2 at 360 K was achieved for the ASP-85 composite film. Meanwhile, this ASP-85 composite film shown the outstanding SET value of 56.1 dB at 52 μm thickness. Flexible Ag2Se/PVDF composite films displayed the excellent thermal energy conversion and EMI shielding capacity.

3D printed SiOC architecture towards terahertz electromagnetic interference shielding and absorption

Electromagnetic interference (EMI) shielding and absorption materials can effectively mitigate the undesired pollution or noise caused by terahertz (THz) waves. The development of THz EMI shielding materials that are primarily based on absorption mechanisms to avoid secondary pollution caused by reflection is still in big demand. Herein, an absorption-dominated precursor-derived SiOC ceramic (PDC-SiOC) architecture for THz wave EMI shielding and absorption was reported. The EMI shielding properties of the bulk SiOC ceramic were studied. More than 93 % of THz EM waves were absorbed by the synthesized SiOC ceramic from 1.2 to 1.6 THz. Furthermore, lightweight honeycomb-structured SiOC architecture which was inspired by the wings of moth was fabricated by vat photopolymerization 3D printing combined with following pyrolysis. The EMI shielding properties and mechanism of the honeycomb SiOC architecture in THz bands were also discussed. The highest shielding effectiveness (SE) of the honeycomb SiOC architecture was up to 64.1 dB, and the transmissivity was below 1.4 % from 0.2 to 1.6 THz. In addition, more than 97–99.8 % of THz waves were absorbed in 0.8–1.6 THz. The excellent EMI shielding performance of the architecture was mainly attributed to its outstanding THz EM wave absorption ability. Finally, the mechanical properties and thermal stability of the architecture were further studied. The compressive and flexural strength of honeycomb architecture was 1.2 and 16.5 MPa, respectively. The result also proved that the honeycomb SiOC architecture was resistant to high temperatures up to 1100 °C under inert atmosphere. This work provides promising high-efficiency architecture towards THz EMI shielding and absorption.

Flexible solid-liquid bi-continuous electrically and thermally conductive nanocomposite for electromagnetic interference shielding and heat dissipation

In the era of 5 G, the rise in power density in miniaturized, flexible electronic devices has created an urgent need for thin, flexible, polymer-based electrically and thermally conductive nanocomposites to address challenges related to electromagnetic interference (EMI) and heat accumulation. However, the difficulties in establishing enduring and continuous transfer pathways for electrons and phonons using solid-rigid conductive fillers within insulative polymer matrices limit the development of such nanocomposites. Herein, we incorporate MXene-bridging-liquid metal (MBLM) solid-liquid bi-continuous electrical-thermal conductive networks within aramid nanofiber/polyvinyl alcohol (AP) matrices, resulting in the AP/MBLM nanocomposite with ultra-high electrical conductivity (3984 S/cm) and distinguished thermal conductivity of 13.17 W m−1 K−1. This nanocomposite exhibits excellent EMI shielding efficiency (SE) of 74.6 dB at a minimal thickness of 22 μm, and maintains high EMI shielding stability after enduring various harsh conditions. Meanwhile, the AP/MBLM nanocomposite also demonstrates promising heat dissipation behavior. This work expands the concept of creating thin films with high electrical and thermal conductivity.

Emulsion-Based Multiscale Structural Design Realizes Lightweight and Superelastic Graphene Aerogels for Electromagnetic Interference Shielding.

Ultralight graphene aerogels with high electrical conductivity and superelasticity are demanded yet difficult to produce. A versatile emulsion-based approach is demonstrate to optimize multiscale structure of lightweight, elastic, and conductive graphene aerogels. By constructing Pickering emulsion using graphene oxide (GO), poly (amic acid) (PAA), and octadeyl amine (ODA), micron-level close-pore structure is realized while thermal shrinkage mismatch between GO and PAA creates numerous nanowrinkles during thermal annealing. GO nanosheets are bridged by PAA-derived carbon, enhancing the structural integrity at molecular level. These multiscale structural features facilitate rapid electron transport and efficient load transfer, conferring graphene aerogels with intriguing mechanical and electromagnetic interference (EMI) shielding properties. The emulsion-based graphene aerogel with an ultralow density of ≈3.0mg cm-3 integrates outstanding electrical conductivity, air-caliber thermal insulation, high EMI shielding effectiveness of 75.0dB, and 90% strain compressibility with superb fatigue resistance. Intriguingly, thanks to the gel-like rheological behavior of the emulsion, ultralight graphene scaffolds with programmable geometries are obtained by 3D printing. This work provides a general approach for the preparation of ultralight and superelastic graphene aerogels with excellent EMI shielding properties, showing broad application prospects in various fields.

High‐efficiency electrothermal and electromagnetic interference shielding performance of expanded graphite/silicone film

AbstractExpanded graphite (EG) is a desired filler for electrothermal and electromagnetic interference (EMI) shielding because of its easy access, low‐cost, lightweight, high conductivity, and heat sensitivity. Herein, fluffy EG was prepared from natural flake graphite (NFG) by a simple expansive technology and subsequently heat treatment at 800°C for 2.0 h in 5% Ar/H2 atmosphere. EG/silicone films with a filling ratio of 15 wt% were obtained via hot‐pressing, which exhibited sensitive electrothermal and excellent EMI shielding performances. When the applied voltages were 5.0, 10.0, and 15.0 V, the steady‐state temperatures were 54.0, 136.5, and 237.8°C in the 30s, respectively. Meanwhile, their average EMI shielding efficiency was greater than 20 dB in 2–18 GHz at 0.84 mm, which was 6.3 times as much as NFG/silicone film. Therefore, this study offers a simple and effective strategy for preparing excellent electrothermal‐EMI shielding materials.Highlights Fluffy EG is prepared by a simple expansive method and treatment at 800°C. EG/silicone films exhibit good electrothermal and EMI shielding performances. Steady temperatures of 55.0/136.5/237.8°C are gotten at 5/10/15 V in 30 s. The EMI shielding efficiency is greater than 20 dB at 0.84 mm. Good properties are due to the EG with high conductivity and fluffy structure.

Construction of rGO-MXene@FeNi/epoxy composites with regular honeycomb structures for high-efficiency electromagnetic interference shielding

With the rapid development of 5G communication technology and wearable electronic devices, the demand for low-reflection electromagnetic interference (EMI) shielding materials is becoming increasingly urgent. In this work, reduced graphene oxide-MXene (rGMH) @FeNi/epoxy EMI shielding composites with a regular honeycomb structure were successfully prepared by the combination of surface functionalization modification, sacrificial template, and freeze-drying. The effects of magnetic FeNi alloy particle loading mode and loading amount on the EMI shielding performance of composites were investigated. The results show that rGMH@FeNi/epoxy EMI shielding composites have the highest EMI shielding effectiveness (EMI SE) and the lowest reflection shielding effectiveness when magnetic FeNi alloy particles are loaded only on the graphene skeleton. In this composite, the EMI SE value of the composite is 61 dB when the rGMH@FeNi mass fraction is 5.4 wt% (f-FeNi mass fraction is 0.9 wt%), which is 4.7 times that of the blended rGO/MXene/FeNi/ epoxy resin composite (13 dB) with the same mass fraction. At the same time, the rGMH@FeNi/epoxy composite has excellent thermal stability (heat-resistance index of 190.3 °C) and mechanical properties (energy storage modulus of 8606.7 MPa). These polymer-based EMI shielding composites with excellent EMI shielding properties and low reflection effectiveness have great potential in the protection of high-power, portable and wearable electronic devices against electromagnetic pollution.

MXene grafted porous carbon cloth with alumina for high thermal conductivity and EMI shielding effect

Thermal interface material (TIM) has a great potential for efficient heat management and safety of electronic devices. However, achieving high performance polymer-based TIM is still challenging because of its intrinsic thermal conductivity and weak mechanical properties. In particular, electromagnetic interference shielding effect (EMI SE) of polymer-based composites has a great attraction according to electronic devices have become ubiquitous, playing integral roles in everyday life in our increasingly interconnected world. Herein, a porous carbon cloth (CC) for use as a continuous thermally and electrically conductive template is prepared via a freeze-casting method, after which mxene (MX) is chemically grafted onto the CC surface. Then, the as-prepared MX-CC is used along with alumina (AO) to fill a poly vinyl alcohol (PVA) matrix in order to fabricate a thermally conductive film with electromagnetic interference (EMI) shielding properties. The resultant composite demonstrates remarkable characteristics, including an excellent EMI shielding effect of 28 dB, substantial tensile strength of 19 MPa, and impressive out of plane thermal conductivity (3.98 W/mK). When applied to a light-emitting diode (LED), the PVA/MX-CC/AO composite effectively manages heat, thereby resulting in a 49 °C reduction in the operating temperature. Therefore, the composites developed herein hold great promise for improving thermal management in electronic devices.

A flexible and strong mechanical MXene/CNC electromagnetic shielding film with powerful light-to-heat conversion properties

High-performance electromagnetic interference (EMI) films with high EMI shielding efficiency, low thickness, high mechanical strength, and flexibility have promising applications in electromagnetic (EM) protection of electronic products. Here, a versatile and sustainable wearable EM shielding MXene/cellulose nanocrystals (CNC) composite film was developed by a simple vacuum-assisted filtration method. One-dimensional (1D) ultrafine CNC act as interfacial linkage enhancers, forming a dense ‘mortar-brick’ structure between CNC and MXene nanosheets, which improves the mechanical properties while maintaining the EMI shielding capability of the films. The obtained films show the better tensile strength (83 MPa) than the pure MXene film (12 MPa). More importantly, the MXene/CNC film exhibits excellent EMI shielding, with an EMI SE of nearly 30 dB at a very low thickness of 7 μm, and 64.5 dB at a thickness of 61 μm. In addition, the films possess good mechanical stability, which can be rapidly heated up to 76 ⁰C and remain stable for a long time. This study provides a promising strategy for the design of multifunctional flexible EMI shielding materials.

Ultrahigh absorption dominant EMI shielding polyimide composites with enhanced piezoelectric property

Piezoelectric sensors have been widely used in wearable electronic devices with improved integration, which is prone to cause electromagnetic interference (EMI) pollution and affects its operation stability. How to design the materials with integrated piezoelectric sensing and EMI shielding performance is of great significance. In this paper, the Fe3O4@PPy/PINF (FPN) composite film was prepared by depositing pyrrole (Py) on the surface of Fe3O4 nanoparticles and combining it with polyimide (PI) nanofibrous membrane via vacuum-assisted suction filtration. In addition, after encapsulation with a highly soluble fluorine-containing polyimide (FPI) resin, a structurally stable FPI-Fe3O4@PPy/PINF (PFPN) composite film was obtained. The prepared PFPN composites show excellent EMI shielding effectiveness (44.58 dB) through the secondary reflection and multiple absorption effects. Remarkably, the value of the absorption coefficient A can reach 0.74, showing outstanding absorption characteristics. In addition, PFPN composite film also shows unexpected piezoelectric properties with high sensitivity of S = 0.8, short response (25 ms) and recovery (45 ms) time. Its piezoelectric output can reach 4.2 V with stable cyclic output property (>15000 times). This kind of composite film with ultra-low reflection characteristics and favorable piezoelectricity presents a wide range of potential applications in the self-powered wearable electronic fields.

Constructing multi-dimensional alternating layer nested structure for enhancing electromagnetic shielding, thermal management and strain sensing

It is imperatively desired to design excellent electromagnetic interference (EMI) shielding and thermal management simultaneously. Herein, fabricating the multi-dimensional alternating layer nested (MALN) structure composite film, which consisted of the alternating multilayer structure constructed by silver nanowires (AgNWs)/cellulose nanofiber (CNF) layer and the graphene nanoplates (GNPs)/CNF layer, the dense conducting networks built by interweaving AgNWs in CNF networks, and the “mille-feuille” structure of GNPs and CNF. The heterogeneous layers of AgNWs/CNF layer and GNPs/CNF layer with significant conductivity differences, as well as the “mille-feuille” structure of CNF and GNPs, provide abundant macro/micro heterogeneous interface polarization losses and multiple reflection losses. Adjusting the addition of AgNWs or GNPs in different layers to form the conductivity gradient, endowing the “absorption-reflection–absorption” loss path and excellent conduction loss of film. Therefore, the MALN structure composite film with a thickness of 90 μm exhibits an impressive EMI shielding efficiency (SE) of 98.95 dB and a specific SE (SSE/t) of 11606.14 dB/g·cm−2, attribute to its excellent conduction loss, abundant macroscopic/microcosmic heterogeneous interfacial polarization losses, multiple reflection losses, and the absorption-reflection–absorption loss path. Meanwhile, the in-plane thermal conductivity (λ∥) and out-plane thermal conductivity (λ⊥) achieve of 8.69 W/(m·k) and 0.16 W/(m·k). Additionally, the obtained film also demonstrates exceptional joule heating, remarkable photothermal conversion, outstanding mechanical properties, and distinguished strain sensing capabilities, which exhibiting significant potential in wearable electronic devices.

Electromagnetic Interference (EMI) Shielding and Thermal Management of Sandwich-Structured Carbon Fiber-Reinforced Composite (CFRC) for Electric Vehicle Battery Casings.

In response to the growing demand for lightweight yet robust materials in electric vehicle (EV) battery casings, this study introduces an advanced carbon fiber-reinforced composite (CFRC). This novel material is engineered to address critical aspects of EV battery casing requirements, including mechanical strength, electromagnetic interference (EMI) shielding, and thermal management. The research strategically combines carbon composite components with copper-plated polyester non-woven fabric (CFRC/Cu) and melamine foam board (CFRC/Me) into a sandwich-structure composite plus a series of composites with graphite particle-integrated matrix resin (CFRC+Gr). Dynamic mechanical analysis (DMA) revealed that the inclusion of copper-plated fabric significantly enhanced the stiffness, and the specific tensile strength of the new composites reached 346.8 MPa/(g/cm3), which was higher than that of other metal materials used for EV battery casings. The new developed composites had excellent EMI shielding properties, with the highest shielding effectives of 88.27 dB from 30 MHz to 3 GHz. Furthermore, after integrating the graphite particles, the peak temperature of all composites via Joule heating was increased. The CFRC+Gr/Me reached 68.3 °C under a 5 V DC power supply after 180 s. This research presents a comprehensive and innovative approach that adeptly balances mechanical, electromagnetic, and thermal requirements for EV battery casings.

Novel fire-resistant SiBCN fiber paper with efficient electromagnetic interference shielding and Joule-heating performance

Since electromagnetic interference (EMI), icing, and fire incidents greatly threaten aviation safety, multifunctional EMI shielding materials are urgently required in the aviation industry. However, developing highly efficient EMI shielding materials that combine fire resistance and thermal management remains a significant challenge. Here, a novel fire-resistant SiBCN ceramic fiber paper with excellent EMI shielding and Joule heating performance was fabricated via electrospinning followed by cross-linking, pyrolysis, and annealing. Compared with the SiBCN fiber paper prepared at 800 °C with poor EMI shielding performance, the total shielding effectiveness (SET) of the SiBCN fiber paper annealed at 1400 °C significantly increased to 21 dB, with specific shielding effectiveness (SSE/t) as high as 3317 dB•cm2•g−1, due to the precipitation of “island-like” conductive turbostratic C, facilitating the synergistic effects of conduction loss, dipole polarization, and interfacial polarization, resulting in high efficiently attenuation of the electromagnetic waves (EMW). Furthermore, the fiber paper demonstrated excellent fire-resistant and Joule-heating performance, with a rapid electrothermal conversion response and a high saturation temperature of 300 °C at 12 V. Therefore, this work proposes a novel strategy for designing multifunctional ceramic fiber paper with integrated EMI shielding, fire resistance, and Joule heating performance for aircraft safety.