Composite Energy Storage Research Articles

Rationally engineering a binary SnS0.5Se0.5/carbon nest-coated Si nanosphere for a high-performance lithium-ion battery anode

A nanohybrid composed of core-nest structured Si@SnS0.5Se0.5/carbon is developed using silicon as the core and SnS0.5Se0.5/carbon as a binary nest, displaying a high performance, which is significant for engineering many energy-storage composites.

Experimental study of phase transition heat of composite thermal energy storage materials paraffin wax/expanded graphite

In this paper, the effect of the expanded graphite (EG) matrix on the phase transitions enthalpy of phase change material (PCM) is studied experimentally. For this purpose, the paraffin wax (PW) containing EG (up to 6.5 wt%) was explored in terms of the effective heat capacity and a diffuse phase transitions enthalpy difference over the 25–65 °С temperature range. Composite PCMs PW/EG was prepared using a new method and were inherent in high pores fill factor. The main advantage of the proposed method is preliminary vacuuming of the PW and EG with subsequent mixing and sonication under vacuum. The EG choice was based on the hypothesis that the EG matrix contributes to modifying the PW internal structure due to the PW molecules' adsorption on the EG surface during PCM cooling and solidification. Consequently, a significant change in PW/EG caloric properties vs. pure PW was observed. The EG presence in PW reverses the enthalpy hysteresis in the heating-cooling cycle vs. pure PW. The enthalpy difference during PW heating and melting in the range of 30–60 °С is higher than during its cooling and solidification: 336.2 J∙g−1 vs. 214.9 J∙g−1. On the contrary, the enthalpy difference of melting for PW/EG of 3.6 wt% in the range 30–60 °С was 171.2 J∙g−1 vs. 273.8 J∙g−1 during solidification. The obtained results are explained by the different dynamics of processes of PW melting and solidification in EG matrix pores. The presence of the 3.2–6.5 wt% of EG in PW contributes to an increase in solidification enthalpy difference in the range 30–60 °C on 27–33 % vs. pure PW. A decrease in the melting enthalpy difference for PW/EG on 44–50 % vs. pure PW was recorded in the range of 30–60 °C. In addition, thermal conductivity was measured to confirm the advantages of PW/EG as PCM. Thermal conductivity for PW/EG with EG content of 3.6 and 6.5 wt% at 25 °C was 8.9 and 9.6 times higher than for pure PW. Similarly, 8.8 and 10.9 times thermal conductivity increase was observed at 65 °C. The composite PCM containing 3.6 wt% of EG in PW obtained by developed method can be recommended as a rational composition in benefit of the thermal conductivity and caloric properties for utilization in high-performance TES systems.

Energy storage and hydrophobicity characteristics of cement-based materials containing paraffin-pumice at low air pressure

Pumice is an environmental friendliness and low-cost carrier material for development of paraffin-pumice phase change energy storage composites (PP) at low air pressure in this work. PP was incorporated into cement to obtain CBM-PP. Microstructural, chemical, and thermal characteristics of PP were investigated by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) tests. Moreover, thermal energy storage and hydrophobicity characteristics of CBM-PP were performed by thermal conductivity, drip, and water absorption experiments. Results show that paraffin is effectively impregnated into pumice pores. There exists a physical interaction between paraffin and pumice. And PP possesses excellent compatibility and thermal stability, while its phase change temperatures and thermal energy storage capacities are in the ranges of 51.84–54.69 °C and 77.22–110.60 J/g, respectively. Furthermore, CBM-PP possesses excellent thermal energy storage and hydrophobicity at low air pressure in plateau areas, thus exhibiting a good application prospect in building thermal management and impermeability. Moreover, the thermal conductivity variation of CBM-PP is studied by the thermal conductivity model, which can predict the thermal conductivity with an error of no >9 %.

A series of formic acid MOFs/polylactic acid blending composites with the improved dielectric performance in Co(II) systems

In order to improve the limited compatibility of existing polymer/ceramic dielectric composites and further enhance the energy storage density, MOF/polymer composite dielectrics have been explored, which exhibit good compatibility to the polymer matrix from abundant organic groups of the inorganic–organic hybrid metal-organic framework (MOF) fillers. However, they still lack a clear composition–structure–property rule, and the precise design of MOF fillers and polymer matrix becomes a prominent problem in these composites due to the diversity of the metal ions and the organic groups. Thus, in this paper, we present a series of formic acid MOFs/polylactic acid dielectric composites in which ferroelectric formic acid MOFs, namely PDLLA/[NH[Formula: see text](CH[Formula: see text])[Formula: see text]NH[Formula: see text]][M[Formula: see text](HCOO)[Formula: see text]][Formula: see text] and PDLLA/[CH[Formula: see text]NH[Formula: see text]][M[Formula: see text](HCOO)[Formula: see text]][Formula: see text], in which the formic acid MOFs are with different structures and different metal ions as fillers, including [NH3(CH[Formula: see text]NH3][MII(HCOO)3]2 (namely MOF– Co (M [Formula: see text] Co), MOF– Mg(M [Formula: see text] Mg), MOF– Mn (M [Formula: see text] Mn), with 1, 4-butanediamine ion as guest) and [CH3NH3][M[Formula: see text](HCOO)3]2 (namely MOF– Co[Formula: see text] (M = Co), MOF– Ni[Formula: see text] (Ni), with methylamine ion as guest). The composition and morphology of composite films were characterized by XRD, IR, SEM, DSC and UV, respectively, while the dielectric characterizations of the composites including the dielectric permittivity, the dielectric loss, the breakdown field strength and the energy density were also performed. The composition–structure–property relationships were also investigated including the influence of MOF content and MOF category. With the introduction of MOFs, the dielectric constant of the polylactic acid substrate was improved slightly while the breakdown field strength can be improved in some systems. Interestingly, the Co(II)-containing formic acid MOF has advantages over other formic acid MOFs with similar structure for the enhancement of the dielectric constant and breakdown field strength. Also, in some composite films with methylamine ion guest MOF fillers and low-MOF content ( MOF– Co[Formula: see text] (1 vol.%) and MOF– Ni[Formula: see text] (1 vol.%)), the breakdown electric field enhanced significantly and further led to improved energy storage density which was about 43% higher than that of the polylactic acid matrix. The possible reason is that in these composites, the orientation of C–H bonds of MOFs seems more beneficial to the formation of hydrogen bonds between the carboxyl group of formic acid and the polylactic acid matrix. These relationships obtained from formic acid MOFs/polylactic acid composites are valuable to the design of high-performance polymer/MOF energy storage composites and may be a new perspective to the practical use of ferroelectric MOFs.

Experimental study on the performance of a novel composite phase change energy storage material for clean heating

Experimental study on the performance of a novel composite phase change energy storage material for clean heating

Structural energy storage composites based on modified carbon fiber electrode with metal-organic frame enhancing layered double hydroxide

Structural energy storage composites based on modified carbon fiber electrode with metal-organic frame enhancing layered double hydroxide

Current collectors of carbon fiber reinforced polymer for stackable energy storage composites

Energy storage structural composites combine the function of storing energy with that of bearing mechanical load. Electrode and electrolyte components can simply be laminated to fabricate composite energy devices. We advance here a sheet of carbon fiber fabric interlaced with epoxy resin as a bipolar current collector (CC), which becomes a component of bipolar electrode when coated with an active material and dried. The CC is quite light and its specific strength is an order of magnitude higher than the typical metal CCs. We also advance a sheet of glass fiber fabric, a separator, impregnated with a eutectogel electrolyte as a composite separator/electrolyte component. The ionic conductivity of the electrolyte is excellent over a wide range of temperature and is stable up to 100 °C. Composite supercapacitors are fabricated by alternate stacking of the two component sheets. They are used to verify the scalability of the energy device achievable by the simple lamination and to demonstrate the significant enhancement in the power and energy density attainable by reducing the device weight through the utilization of the bipolar CCs. Practical utility of the stacked supercapacitors is demonstrated.

Plastic composite of bamboo charcoal stabilized polyethylene glycol with thermal energy storage and temperature regulation for building energy efficiency

AbstractPhase change materials (PCMs) are often used as building materials to reduce the energy consumption. However, conventional PCMs are susceptible to leakage and have a short service life. To solve this problem, thermal energy storage (TES) composites were fabricated by using bamboo charcoal (BC) encapsulating polyethylene glycol (PEG) as the PCM and low density polyethylene (LDPE) as the matrix. The shape and structure of BC and BC‐plastic composites were examined using scanning electron microscopy, X‐ray diffractometry, and mercury intrusion porosimetry. Differential scanning calorimetry, thermogravimetry (TG), and infrared thermography were used to characterize the manufactured TES composites. Physical and mechanical strength assessments were also conducted. The results demonstrated that: (1) BC possessed a rich void structure with a porosity of 61.4%, which could be used to adsorb PEG and the composites was a combination of PEG, BC, and LDPE with no chemical reaction; (2) thermal tests demonstrated that the composites exhibited favorable temperature regulation properties, featuring a maximum latent heat capacity of 29.1 J/g along with suitable phase change temperatures, yet thermal durability needs to be improved much further, addition of PEG reduced thermal conductivity of the composite from 0.38 to 0.34 W/mK; (3) the addition of PEG was beneficial for the impact strength but had a negative impact on the flexural and tensile properties; and (4) due to their satisfactory thermal performance and acceptable mechanical properties, these TES composites can be effectively utilized as building materials for temperature control purposes.Highlights Bamboo charcoal (BC) had a large number of pores that can encapsulate polyethylene glycol (PEG). PEG/BC performed satisfactory latent heat. Low density polyethylene was used as the matrix to realize the second encapsulation of phase change material. Thermal energy storage composites had excellent stability and good heat storage capacity. PEG incorporation negatively affected flexural and tensile properties.

Use of phase change materials in wood and wood-based composites for thermal energy storage: A Review

Using phase change materials (PCMs) is an efficient solution for reducing energy consumption in buildings. These materials have a large capacity for storing thermal energy, making them an appealing option for energy management purposes. Phase change materials have been successfully incorporated into various construction materials such as concrete, brick, or plaster. The primary objective of this review is to examine previous studies conducted on the application of PCMs in wood. The initial section presents an overview of the direct impregnation techniques utilized for wooden materials. This is followed by a discussion on the implementation of macroencapsulated PCMs in wooden structures that are typically present in residential buildings. In addition, the use of shape-stabilized PCM/wood composites, preventing potential leaks during the phase change transition, is explored. Finally, patents related to the use of PCMs in wood are described. Future challenges include the incorporation of PCMs into wood composites to improve their thermal properties. This literature review shows that there is a gap in knowledge regarding the utilization of phase change materials in wood-based panels such as oriented strandboards, fiberboards, and particleboards. This provides an opportunity for future research to improve the performance of the products manufactured by the wood-based panels industry.

An energy storage composite using cellulose grafted polyethylene glycol as solid–solid phase change material

AbstractPhase‐change material (PCM) has great thermal energy ability, which has been used as building material for energy conservation. While the most widely used solid–liquid PCM usually appeared leakage during the phase change transition. In order to overcome the leakage of solid–liquid PCM and prepare a viable building energy‐saving materials for indoor temperature regulation, thermal energy storage composites were prepared by utilizing cellulose grafted PEG as phase change material (PCM) and high‐density polyethylene (HDPE) as the substrate. The liquid leakage of PEG was solved after graft to fabricate solid–solid PCM. HDPE is beneficial for solving the leakage and improving the mechanical property by its secondary encapsulation. The synthesized Cellulose‐PEG was characterized by scanning electron microscopy (SEM), X‐ray diffractometer (XRD), and differential scanning calorimetry (DSC). Thermal and mechanical characteristics of the composite were explored. The outcomes revealed that: (1) PEG was successfully grafted to the surface of cellulose and Cellulose‐PEG showed solid–solid phase change behavior. (2) Both the melting‐cooling temperatures and the thermal stability of solid–solid wood plastic composite (SSWPC) had the potential as thermal energy storage material for temperature regulating. (3) The addition of Cellulose‐PEG adversely affected moisture resistance, flexural property, and impact strength due to the weak interface bonding. The physical and mechanical degradation was tolerable for applying situation where mechanical performance is less crucial.Highlights Cellulose‐PEG showed solid–solid phase change behavior without liquid leakage. High‐density polyethylene (HDPE) was used as the matrix to realize the second encapsulation of PCM. Cellulose‐PEG negatively influenced the physical and mechanical property of HDPE. Solid–solid wood plastic composite presented great thermal storage capacity for indoor temperature regulating.

Lamellar sodium titanium silicate assembled by nanostrips decorated with N-rich 3D carbon for sodium dual-ion batteries

Sodium dual-ion batteries have received tremendous attention owing to their appealing operating voltage (i.e. >4.0 V) and eco-friendly features. However, the exploitation of efficient sodium ion storage anode materials is one of the keys for driving the application of sodium dual-ion batteries in the grid-scale energy storage. Herein, a lamellar sodium titanium silicate (NTSO) woven by plentiful nanostrips grown in situ on the surface of N-rich 3D carbon has been prepared via a convenient synthetic strategy. Based on the synergistic effect both micro-nano composite spatial structure and energy storage mechanism based on conversion reaction of material bulk phase, the NTSO/3DC-N composite as anode delivers a high special capacity of 540.6 mAh/g at 0.05 A/g and 163.1 mAh/g at 5.0 A/g in sodium ion half-cell. More impressively, the sodium dual-ion batteries built with NTSO/3DC-N as anode and a N-rich 3D carbon as cathode exhibits a high reversible capacity of about 123.6 mAh/g at 0.05 A/g. The elaborate designing an interconnecting framework composed of layered titanium silicate sodium and heterogeneous atom doping carbon substrate provides a generally applicable strategy for enhancing the anode performance of sodium dual-ion batteries.

Study and optimization on heat storage and release characteristics of a cascaded sensible-latent heat composite energy storage heat sink

The energy storage is an effective solution for the current imbalance between energy supply and demand. In particular, the cascaded storage method can enhance the heat exchange temperature difference and heat storage efficiency. Previous research mainly focused on the combination of different phase change materials, while there was rare research on efficient cascaded conversion pathways for electrothermal direct conversion coupled thermal storage devices. This study investigated the influence of sensible and latent heat storage materials on the thermal performance, and identified the optimal volume ratios and materials types. When the volume share of Mg-Al:PW-EG=1:1, the heat storage performance was the optimal with a quantity/efficiency of heat stored as 7328.7 kJ/97.3 %, leading to an increase of 458.5 kJ/6.6 % than the sensible heat storage condition (Mg-Al:PW-EG=1:0) and 630.18 kJ/8.5 % than the latent heat storage condition (Mg-Al:PW-EG=0:1). When the melting point and latent heat of phase change materials increased from 68.9∼79.1 °C and 224.8 kJ/kg to 118.0 °C and 344.9 kJ/kg respectively, the heat storage temperature rose by 162.7 °C, quantity of heat stored rose by 7535.5 kJ. While materials with large subcooling were not recommended for short-term heat storage, as approximately 25.6 % (3309.3 kJ) of stored heat and 22.4 % (2505.2 kJ) of exergy were wasted when the subcooling degree was 70 °C. The findings provided solutions to support the synergistic enhancement of heat storage/release performance of the composite energy storage heat sink.

In-situ crosslinked polyetherimide/BNNS composites with ultrahigh charged-discharged efficiency at high temperature

High performance dielectric polymer composites for capacitive energy storage have been a hot topic in recent years. However, dielectric materials tend to breakdown at high temperature, and its charged-discharged efficiency is greatly reduced. Therefore, preparing high-efficient high-temperature dielectric material is the main challenge in this field. In this work, based on the synergistic effect of in-situ composite and controlled thermal cross-linking, the thermal conducting nano filler and crosslinking system composite has ultra-high charged-discharged efficiency at high temperature. It is proved that the addition amount of BNNS for the peak performance of this kind of composite is 10 vol% and the discharge energy density is 4.58 J/cm3 and the charged-discharged efficiency reaches 96 % at 150 °C and 500 MV/m. At 200 °C and 300 MV/m, these are 1.76 J/cm3 and astonishing 95 %. It is expected to be a candidate for a new generation of high temperature resistant dielectric materials.

Development of Thermal Energy Storage Material From Blends of Jatropha Biodiesel and Paraffin Wax for Augmenting Freshwater Generation Capacity in a Solar Desalination System

Abstract Enhancing nocturnal productivity holds promise for boosting the effectiveness of solar desalination setups. Current research concentrates on an innovative strategy: the integration of paraffin wax and Jatropha biodiesel as a composite energy storage material (CESM) to amplify distilled water output during nighttime. The composite material, comprising Jatropha biodiesel and paraffin wax in a 1:1 ratio by weight, is meticulously examined for its impact on productivity, juxtaposed against a conventional solar still (CSS). Results reveal a substantial improvement in thermal conductivity with CESM, exhibiting a noteworthy 20.37%% surge compared to pure paraffin wax. Furthermore, a solar still with biodiesel and phase change material (SSBDPCM) is pitted against a CSS, with continuous monitoring of water and absorber temperatures alongside distillate production. The findings illustrate that SSBDPCM achieves a 16% upsurge in water temperature and a 10% elevation in absorber temperature compared to CSS. Impressively, SSBDPCM achieves a staggering 63% increase in distillate production, yielding 3.6 l/m2 and 3.4 l/m2, in sharp contrast to CSS, which only manages 2.2 l/m2 and 2.1 l/m2 over a two-day test period. Furthermore, a comprehensive cost analysis showcases the economic superiority of SSBDPCM over CSS. SSBDPCM demonstrates a compelling 29.2% reduction in cost per liter and a significant 25.9% decrease in the payback period in comparison to CSS. These compelling outcomes underscore the substantial potential of the SSBDPCM approach in delivering heightened efficiency and cost-effectiveness, paving the way for a promising advancement in solar stills.

Synergistic enhancement of phase change materials through three-dimensional macropore lamellar structured MOF/EG composite for solar energy storage and beyond

The concept of high energy storage density, negligible changes in volume and pressure after phase change, approximately constant operating temperature and non-toxic of solid–liquid phase change energy storage are very appealing properties that makes it a good strategy to store heat. However, leakage and single thermal energy storage function has become a bottleneck for the further advances of long-term thermal stability and multifunctionality. It is reassuring to know that Metal-organic frameworks (MOF)-porous carbon materials can offer a solution to continuity challenge for growing demand for multifunctionality in phase change materials (PCMs). Herein, a phase change material (PCM) composite with good shape stability, thermal conductivity, and photothermal conversion capability was designed. EG in the blended system can effectively prevent the agglomeration of ZIF particles while simultaneously providing a high specific surface area and pore volume for the adsorption of paraffin wax. The as-obtained PCM composite possesses a 3-fold enhancement in thermal conductivity, 95.56% photothermal conversion efficiency, and excellent shape stability. It demonstrates the potential of MOFs-enhanced PCM composites for thermal energy storage and highlight the importance of synergistic or hybridization strategies in the development of advanced materials for sustainable energy applications.

Effects of expanded graphite on NaNO3/semi-coke ash shape-stable phase change composites for thermal energy storage

As an alkaline industrial solid waste with a porous structure, semi-coke ash can have adverse effects on the environment if accumulated or buried in large quantities. The research group has previously used this material in combination with NaNO3 to prepare a shape-stable phase change composite. Building upon the previous research team, this work manufactured the shape-stable phase change composite by cold-compression hot-sintering method using NaNO3 as the phase change material, semi-coke ash as the skeleton material and an innovative addition of expanded graphite as the thermal conductivity enhancer to enhance thermal conductivity of phase change material. Then, key thermal performance, mechanical strength, chemical compatibility, microscopic morphology, economic efficiency and emission reduction capacity were investigated. Results demonstrated that the sample SS2 with 0.5 wt% expanded graphite performed best, which also presented a mechanical strength of 113.82 MPa, a thermal conductivity of 1.844 W/(m·K), and an excellent thermal energy storage density of 424.91 J/g between 100–400 °C; Both the thermal performance and mechanical strength of sample SS2 decreased to some extent after the heating/cooling cycles; The semi-coke ash, expanded graphite, and NaNO3 showed excellent chemical compatibility while both the thermal energy storage cost (0.022 ¥/kJ) and the raw material carbon emissions (1041 kg) of producing per ton sample SS2 in this work were far below traditional shape-stable phase change materials.

A high altitude prosumer energy cooperation framework considering composite energy storage sharing and electric‑oxygen‑hydrogen flexible supply

With the ever-increasing penetration rate of distributed renewable energy in the smart grid, the role of consumers is shifted to prosumers, and shared energy storage can be a potential measure to improve the operating income of prosumers. Nevertheless, the energy cooperation strategies of high-altitude prosumers (HAPs) are rarely studied. This study proposes an energy cooperation framework for HAPs, aiming to improve the economic flexibility of HAP operations and promote the cooperation framework. Firstly, a combined oxygen supply model for HAPs is proposed to satisfy the electricity and oxygen supply demand in high-altitude areas. Secondly, a composite energy storage provider (CESP) is introduced to provide electricity‑oxygen‑hydrogen composite energy storage sharing services and to establish an energy cooperation framework between HAPs and CESPs. Moreover, an asymmetric profit distribution model with the contributions of multiple energy sharing is proposed, and a two-stage profit distribution is carried out for CESPs and HAPs. Finally, the multi-scenario analysis and comparison are conducted to assess the overall benefits of the framework. From the research results, the proposed framework outperforms the independent HAPs, and the economic benefits, primary energy saving rate, system independence, and self-sufficiency rate have increased by 1609.91 CNY, 15.00%, 10.75%, and 15.31%, respectively. This study provides a feasible framework for energy cooperation among HAPs, and the framework's effectiveness is well-validated.

Preparation and Characterization of Bio-Based PLA/PEG/g-C3N4 Low-Temperature Composite Phase Change Energy Storage Materials.

As energy and environmental issues become more prominent, people must find sustainable, green development paths. Bio-based polymeric phase change energy storage materials provide solutions to cope with these problems. Therefore, in this paper, a fully degradable polyethylene glycol (PEG20000)/polylactic acid (PLA)/g-C3N4 composite phase change energy storage material (CPCM) was obtained by confinement. The CPCM was characterized by FTIR and SEM for compatibility, XRD and nanoindentation for mechanical properties and DSC, LFA, and TG for thermal properties. The results showed that the CPCM was physical co-mingling; when PLA: PEG: g-C3N4 was 6:3:1, the consistency was good. PEG destroys the crystallization of PLA and causes the hardness to decrease. When PLA: PEG: g-C3N4 was 6: 3: 1, it had a maximum hardness of 0.137 GPa. The CPCM had a high latent enthalpy, and endothermic and exothermic enthalpies of 106.1 kJ/kg and 80.05 kJ/kg for the PLA: PEG: g-C3N4 of 3: 6: 1. The CPCM showed an increased thermal conductivity compared to PLA, reaching 0.30 W/(m·K),0.32 W/(m·K) when PLA: PEG: g-C3N4 was 6: 3: 1 and when PLA: PEG: g-C3N4 was 3: 6: 1, respectively. Additionally, the CPCM was stable within 250 °C, indicating a wide appliable temperature range. The CPCM can be applied to solar thermal power generation, transportation, and building construction.

S, N co-doped rGO/fluorine-free Ti3C2Tx aerogels for high performance all-solid-state supercapacitors

The development of fluorine-free MXene based composites for electrochemical energy storage and conversion devices is considered to be a promising approach. Herein, we used Lewis acid Fe (III) to etch Ti3AlC2 successfully to prepare MXene with in-situ loaded Fe2O3 nanoparticles. The three-dimensional porous aerogels co-doped with S and N were synthesized by the redox self-assembly reaction of MXene and graphene oxide in the hydrothermal condition containing thiourea. XPS results show that S and N heteroatoms can enhance the hydrophilicity and pseudo-capacitance of the composites by changing the electronic structure of adjacent C atoms and forming S-C/N-C bonds. The specific capacitance of the optimized Fe3+-Ti3C2Tx/S,N-rGO-2 is 220.7 F g−1 at 1 A g−1, and the capacitance retention rate is above 80 % after 5000 cycles at a current density of 6 A g−1. The all-solid-state symmetric supercapacitor with Fe3+-Ti3C2Tx/S,N-rGO-2 as electrode materials, and PVA-KOH as electrolyte can work normally in extreme environments of 60 and −20 °C, respectively. This work provides a viable route for the fluorine-free preparation of MXene and its electrochemical application.

Preparation and characterization of bifunctional wolfsbane-like magnetic Fe3O4 nanoparticles-decorated lignin-based carbon nanofibers composites for electromagnetic wave absorption and electrochemical energy storage

Recently, with the pursuit of high-efficiency electromagnetic wave absorption (EMWA) and electrochemical energy storage (EES) materials, multifunctional lignin-based composites have attracted significant interest due to their low cost, vast availability, and sustainability. In this work, lignin-based carbon nanofibers (LCNFs) was first prepared by electrospinning, pre-oxidation and carbonization processes. Then, different content of magnetic Fe3O4 nanoparticles were deposited on the surface of LCNFs via the facile hydrothermal way to produce a series of bifunctional wolfsbane-like LCNFs/Fe3O4 composites. Among them, the synthesized optimal sample (using 12 mmol of FeCl3·6H2O named as LCNFs/Fe3O4–2) displayed excellent EMWA ability. When the minimum reflection loss (RL) value achieved −44.98 dB at 6.01 GHz with an thickness of 1.5 mm, and the effective absorption bandwidth (EAB) was up to 4.19 GHz ranging from 5.10 to 7.21 GHz. For supercapacitor electrode, the highest specific capacitance of LCNFs/Fe3O4–2 reached 538.7 F/g at the current density of 1 A/g, and the capacitance retention remained at 80.3 %. Moreover, an electric double layer capacitor of LCNFs/Fe3O4–2//LCNFs/Fe3O4–2 also showed a remarkable power density of 7755.29 W/kg, outstanding energy density of 36.62 Wh/kg and high cycle stability (96.89 % after 5000 cycles). In short, the construction of this multifunctional lignin-based composites has potential applications in electromagnetic wave (EMW) absorbers and supercapacitor electrodes.