Conductivity Of Carbon Nanotubes Research Articles

Selective Oxidation of sp-Bonded Carbon in Graphdiyne/Carbon Nanotubes Heterostructures to Form Dominant Epoxy Groups for Two-Electron Oxygen Reduction.

Two-electron oxygen reduction reaction (2e- ORR) is of great significance to H2O2 production and reversible nonalkaline Zn-air batteries (ZABs). Multiple oxygen-containing sp2-bonded nanocarbons have been developed as electrocatalysts for 2e- ORR, but they still suffer from poor activity and stability due to the limited and mixed active sites at the edges as well as hydrophilic character. Herein, graphdiyne (GDY) with rich sp-C bonds is studied for enhanced 2e- ORR. First, computational studies show that GDY has a favorable formation energy for producing five-membered epoxy ring-dominated groups, which is selective toward the 2e- ORR pathway. Then based on the difference in chemical activity of sp-C bonds in GDY and sp2-C bonds in CNTs, we experimentally achieved conductive and hydrophobic carbon nanotubes (CNTs) covering O-modified GDY (CNTs/GDY-O) through a mild oxidation treatment combined with an in situ CNTs growth approach. Consequently, the CNTs/GDY-O exhibits an average Faraday efficiency of 91.8% toward H2O2 production and record stability over 330 h in neutral media. As a cathode electrocatalyst, it greatly extends the lifetime of 2e- nonalkaline ZABs at both room and subzero temperatures.

Biodegradable polylactic acid emulsion ink based on carbon nanotubes and silver for printed pressure sensors

Investigating biodegradable and biocompatible materials for electronic applications can lead to tangible outcomes such as developing green-electronic devices and reducing the amount of e-waste. The proposed emulsion-based conducting ink formulation takes into consideration circular economy and green principles throughout the entire process, from the selection of materials to the production process. The ink is formulated using the biopolymer polylactic acid dissolved in a sustainable solvent mixed with water, along with conductive carbon nanotubes (CNTs) and silver flakes as fillers. Hybrid conductive fillers can lower the percolation threshold of the ink and the production costs, while maintaining excellent electrical properties. The coating formed after the deposition of the ink, undergoes isothermal treatment at different temperatures and durations to improve its adhesion and electrical properties. The coating’s performance was evaluated by creating an eight-finger interdigitated sensor using a Voltera PCB printer. The sensor demonstrates exceptional performance when exposed to various loading and unloading pressures within the 0.2–500.0 kPa range. The results show a consistent correlation between the change in electrical resistance and the stress caused by the applied load. The ink is biodegradable in marine environments, which helps avoiding its accumulation in the ecosystem over time.

Cationic UV-curing of bio-based epoxidized castor oil vitrimers with electrically conductive properties

The growing appeal of carbon nanotube composites in the contemporary market derives from their exceptional thermal and chemical stability, coupled with electrical conductivity. In this study, we combined these salient features with a biobased epoxy matrix having vitrimeric properties, hence being reprocessable and resheapable, to obtain a biobased conductive coating. Epoxidised castor oil (ECO) was chosen as a monomer precursor for the straightforward synthesis. The synthesis relied on a cationic UV-curing process, embedding the conductive carbon nanotubes in the matrix. Photo DSC and transmission FTIR analysis were conducted to determine the final conversion of the epoxy rings in the cationic photocuring process. Thermo-mechanical properties were evaluated by tensile tests, and DMTA. Thermal stability was assessed by TGA. Dielectric spectroscopy confirmed increased electrical conductivity in the presence of increasing CNT content, reaching a percolation threshold at 0.5 phr of CNTs. Vitrimeric properties were proved by stress relaxation experiments, and the UV-cured composite underwent a thermo-activated transesterification reaction starting from 70 °C, catalysed by dibutyl phosphate. Overall, the ECO-CNT composite showed high thermal resistance (up to 400 °C) electrical conductivity with 0.5 phr CNT concentration, and vitrimeric properties. The study can be, therefore, considered a promising starting point to obtain sustainable biobased and electrically conductive vitrimers.

Electrospun thermoplastic polyurethane membrane decorated with carbon nanotubes: A platform of flexible strain sensors for human motion monitoring

A piezoresistive flexible strain sensor was developed using thermoplastic polyurethane elastomers (TPU) as the matrix and carbon nanotubes (CNTs) as conductive fillers. Sensitivity, strain range, and tensile cycling stability were concurrently considered during its design. Electrospun TPU fiber membranes were prepared via electrospinning in this experiment, with controllable fiber diameter achieved by adjusting the rotational speed of the electrospinning receiving drum. CNTs were incorporated into a flexible polymer substrate through suction filtration to create the strain sensor. The support structure of the electrospun film served as a carrier for uniformly adhering conductive particles. Well-dispersed conductive CNTs could more easily achieve uniform loading through the pore size of the electrospun fiber film, thereby forming a conductive layer. This study initially determined the influence of TPU content in the spinning solution on the morphology of the electrospun membrane. Subsequently, the effects of CNT content and electrospinning receiving drum rotational speed on the microstructure of TPU electrospun membranes were investigated, along with their impact on the microstructure, mechanical properties, and sensing performance of CNTs/TPU (CT) flexible strain sensors. The results indicate that the electrospun fiber membrane prepared under the conditions of TPU mass fraction of 20 wt% and rotational speed of 100 r/min has a larger average fiber diameter and a more stable scaffold structure. The CNTs/TPU (CT) sensor, prepared by filtering 10 mL of CNTs with a concentration of 2 mg/mL, exhibited the best mechanical properties, with a tensile strength and elongation at break of 6.22 MPa and 575 %, respectively. Additionally, it demonstrated high sensitivity (GF = 420.17 at 200 % strain) and excellent durability stability (300 cycle tests), enabling quick and accurate responses to movements of various parts of the human body, thereby meeting the basic usage requirements of flexible strain sensors.

Carbon nanotube reinforced FeMoO4 nanorods as a high-performance anode for sodium-ion batteries

Iron molybdate (FeMoO4) nanostructures show great promise as a superior anode for sodium-ion batteries. However, its use in practical application is hampered by its poor electronic conductivity, large volume changes and sluggish reaction kinetics. Herein, we have developed an interconnected network of multiwall carbon nanotube (CNT) and FeMoO4 (FMO) by a simple one-step hydrothermal method. As well as providing efficient channels for charge transfer and diffusion, highly conductive CNTs also have a degree of volume elasticity and excellent electrical conductivity to ensure migration of sodium ions, enabling both fast kinetics and long-term stability. As a result, the FMO@CNT anode delivers a high reversible capacity of 485 mA h g−1 at 0.05 A/g and very long cycling stability with a capacity of 75 mA h g−1 after 1000 cycles at 1 A/g. Furthermore, by combining the ex-situ X-ray diffraction, ex situ X-ray photoelectron spectroscopy and cyclic voltammetry results, sodium ion storage mechanism of the FMO@CNT electrode obeys a conversion mechanism. The results of this work provide a better understanding on the sodium ion storage mechanism of binary metal oxides.

Platinum Nanoparticles Bonded with Carbon Nanotubes for High-Performance Ampere-Level All-Water Splitting.

Platinum nanoparticles loaded on a nitrogen-doped carbon nanotubes exhibit a brilliant hydrogen evolution reaction (HER) in an alkaline solution, but their bifunctional hydrogen and oxygen evolution reaction (OER) has not been reported due to the lack of a strong Pt-C bond. In this work, platinum nanoparticles bonded in carbon nanotubes (Pt-NPs-bonded@CNT) with strong Pt-C bonds are designed toward ultralow overpotential water splitting ability in alkaline solution. Benefit from the strong interaction between platinum and high conductivity carbon nanotube substrates through the Pt-C bond also the platinum nanoparticles bonded in carbon nanotube can provide more stable active sites, as a result, the Pt-NPs-bonded@CNT exhibits excellent hydrogen evolution in acid and alkaline solution with ultralow overpotential of 0.19 and 0.23 V to reach 1000 mA cm-2, respectively. Besides, it shows superior oxygen evolution electrocatalysis in alkaline solution with a low overpotential of 1.69 V at 1000 mA cm-2. Furthermore, it also exhibits high stability over 110 h against the evolution of oxygen and hydrogen at 1000 mA cm-2. This strategy paves the way to the high performance of bifunctional electrocatalytic reaction with extraordinary stability originating from optimized electron density of metal active sites due to strong metal-substrate interaction.

Synergistic multi-functional N-doped carbon Nanocage@CNT/ZnMn2O4/Ti3C2 MXene: Powering battery, supercapacitor, and catalyzing hydrogen evolution

This study presents a novel approach to enhance the electrochemical capabilities of 3D pyrolytic carbon for energy applications. Using a chemical blowing technique, highly conductive carbon nanotubes (CNTs) are embedded within a 3D N-doped carbon nanocage (NCN). This integration involves an additional carbon source during Ni(NO3)2 induced polymer blowing, leveraging the dual role of Ni(NO3)2 in polymer expansion and catalyzing CNT growth. Our research merges ZnMnO4/Ti3C2 with high-capacity N-Doped Carbon Nanocage@CNT (NCN/CNT@ZnMnO4/Ti3C2) to amplify electrochemical performance. The NCN/CNT@ZnMnO4/Ti3C2 showed specific capacitance of 1843 Cg-1 at 1.0 Ag-1, attributed to augmented electrical conductivity and charge storage characteristics. The supercapattery configuration maintains a specific capacitance of 195 Cg-1 at 1.0 Ag-1, cyclic stability of 95% over 18,000 cycles, and a power density of 1145 W-kg−1 at an energy density of 67 Wh-kg−1. In HER applications, NCN/CNT@ZnMnO4/Ti3C2 demonstrates a lower Tafel slope of 56.41 mV-dec−1, signifying a significant advance in high-performance supercapacitors.

Multiwall carbon nanotube-hyperbranched polymaleimide core–shell nanowires with hierarchical porous and polar structure as sulfur host for sustainable lithium-sulfur batteries

Lithium–sulfur (Li–S) batteries have gained considerable attention as a promising alternative to current advanced batteries because of their low cost, natural abundance, high energy density, and environmental benignity of sulfur. The commercial application of Li–S batteries is being seriously impeded by the shuttle effect of lithium polysulfides (LiPSs) and the sluggish reaction kinetics of solid phase transformation. Herein, a novel composite material (PPI@MWCNT-Y) with a hierarchical porous skeleton and polar channel is prepared as a sulfur host using a convenient in-situ one-pot polymerization. PPI@MWCNT-Y is composed of conductive mesoporous multi-wall carbon nanotubes (MWCNTs) core and a microporous hyperbranched polymaleimide (PPI) shell formed by the self-polymerization of N,N′-1,4-phenylenedimaleimide (PDM). The mesoporous and conductive channels in PPI@MWCNT-Y improve the redox kinetics of the active materials by serving as a fast electron and Li-ions transportation pathway. The microporous structure and abundant adsorption sites (N and O atoms) within the PPI@MWCNT-Y served as physical and chemical barriers, preventing the loss of LiPSs, and suppressing the shuttle effect. Consequently, the S/PPI@MWCNT-38 composite exhibited a high discharge capacity of 1338 mAh g−1 at 0.2 C and a low-capacity decay rate of 0.088% for 400 cycles at 1 C.

Carbon nanotubes anchored SiOx composite anode for high cyclic stability lithium-ion batteries

Silicon suboxide (SiOx, 0 < x < 2) is one of the most promising anode materials because of its high lithium-ion storage capacity. However, the poor intrinsic conductivity and large volume change during cycling limits its practical application as lithium-ion battery anode materials. Herein, we propose a novel strategy to introduce carbon nanotubes (CNTs) on the SiOx particles, forming a conductive network and relieving the volume expansion effect, which possess improved reversible capacity and robust structure for long cycling stability. The SiOx/CNT composite anode delivers reversible capacity of 1533.8 mAh g−1 at the first cycle and maintains 599.6 mAh g−1 after 500 cycles with a high coulombic efficiency of 99.7 %. In this paper, SiOx composite anchored by CNTs was prepared, which is a simple and effective strategy to improve the conductivity of SiOx, relieve the volume effect and further promote its electrochemical performance benefit from the high conductivity and structural stability of CNTs. This research provides a significant reference for constructing the delicate structure of SiOx-based composites to enhance cyclic performance.

CoNi hexacyanoferrate nanoparticles anchored on carbon nanotubes as superior cathode materials for rechargeable aqueous zinc-ion batteries

Prussian blue analogues (PBAs) have attracted growing interest as competitive cathode materials for aqueous zinc-ion batteries (AZIBs). However, their low conductivity and easy structural collapse often lead to poor reversible capacity and cyclability. Herein, cobalt‑nickel hexacyanoferrate (CoNiHCF), a CoNi-Prussian blue analogue, are designed as AZIBs cathode materials for the first time, in which highly uniform CoNiHCF nanocubes are in-situ decorated on carbon nanotubes (CNTs) via a simple co-precipitation method. The resulted CoNiHCF/CNTs composite displays superior zinc ion storage performance, with a great reversible capacity of 124.9 mAh g−1 at the current density of 50 mA g−1, and a high capacity retention of 81.8 % at 3000 mA g−1 for 1000 cycles, which are remarkably superior to those of CoHCF, NiHCF and CoNiHCF. The excellent Zn2+ storage properties of CoNiHCF/CNTs can be ascribed to the bimetallic synergistic effect of Co and Ni as well as the introduction of conductive CNTs skeleton. This study offers a straightforward and efficient method for promoting the application of PBAs-based cathodes in AZIBs.

In‐suit synthesis of FeP/C/CNT composites with excellent performance in supercapacitors and lithium‐ion batteries

AbstractIron phosphide (FeP) is a promising electrochemical energy storage material due to easy to obtain and high theoretical capacity. However, the intrinsic poor conductivity and the large volume change during charging and discharging process, result in a sharp decline in capacity and short cycle life for FeP. In this work, the FeP/C/CNT nanocomposite was synthesized efficiently and conveniently by one‐step solid‐phase synthesis method. Amorphous carbon‐coated FeP particles are embedded in a three‐dimensional network structure composed of highly conductive carbon nanotubes, drastically enhancing the conductivity of FeP and reducing the volume expansion during charging and discharging. In the three‐electrode system, the FeP/C/CNT composites showed good electrochemical performance, with a specific capacity as high as 124.4 mAh g−1 at 1 A g−1. Meanwhile, the constructed Ni2P@C/CNT//FeP/C/CNT asymmetric supercapacitor delivered a high energy density (70.73 Wh kg−1), power density (7.9 kW kg−1) and a long cycle life (10000 cycles). In addition, as served as an anode material in the lithium ion battery, the FeP/C/CNT composite also displayed as high as 601.8 mAh g−1of specific capacity at 0.1 A g−1 and a good cycle stability, showing superior electrochemical performance. The above work provides a promising composite material for supercapacitors and lithium ion batteries. Moreover, the solid‐state preparation methods can provide a reference for the synthesis of transition metal phosphides.

Efficient Co0.85Se-CNT sulfur cathode derived from strong catalyst-support interactions: Contribution of adsorption-catalysis mechanism to the redox kinetics of polysulfides

The sluggish conversion chemistry and the notorious ‘shuttle effect’ of lithium polysulfides (LiPSs) are hindering the widespread application of lithium-sulfur batteries (LSBs). Herein, N-doped carbon nanotubes arrays anchored with highly dispersed Co0.85Se nanoparticles were in-situ grown on 3D carbon paper substrates (Co0.85Se-CNT@CP) to promote redox kinetic. The derived sulfur cathode (S/Co0.85Se-CNT@CP) exhibited a sufficient chemisorption ability to accelerate the conversion kinetics and showed considerable capability (1210 mAh/g at 0.2C) and impressive cyclic stability (516 mAh/g at 2.0C after 500cycles). Even at a high loading of 6.0 mg cm−2, the assembled batteries performed a high capacity of 500 mAh/g at 2.0C after 500cycles. The exceptional performance is attributed to the following reasons: On the one hand, the highly efficient conductive carbon nanotubes not only offer sufficient accommodation space for sulfur, but also provide physically confinement for polysulfides. On the other hand, the Co0.85Se nanoclusters drove the transformation of more elemental sulfur to Li2S2/Li2S. In addition, the S/Co0.85Se-CNT@CP did not require conventional binders, thus enhanced surface the reaction kinetic and electron transfer. The associated conversion mechanism was studied by ex-situ XPS, and an adsorption-catalytic model was established to elucidate the electrochemical mechanism. This study proposes a feasible strategy to solve the severe LiPSs shuttling and the sluggish conversion kinetics of LSBs.

High-performance VO2/CNT@PANI with core–shell construction enable printable in-planar symmetric supercapacitors

As a progressive electronic energy storage device, the flexible supercapacitor holds tremendous promise for powering wearable/portable electronic products. Of various pseudocapacitor materials, vanadium dioxide (VO2) has garnered extensive attention due to its impressive theoretical capacitance. However, the challenges of inferior cycling life and lower energy density to be addressed. Herein, we prepare VO2 nanorods with winding carbon nanotubes (CNT) via a facile solvothermal route, followed by in situ polymerization of polyaniline (PANI) shell. Taking full advantage of the synergistic effect, the VO2/CNT@PANI composite delivers a high specific capacitance of 354.2F/g at 0.5 A/g and a long cycling life of ∼ 88.2 % over 5000 cycles resulting from the enhanced conductivity of CNT and stabilization of PANI shell. By screen printing the formulated inks with outstanding rheological behaviours, we manufacture an in-planar VO2/CNT@PANI symmetric supercapacitor (VO2/CNT@PANI SSC) device featuring an orderly arrangement structure. This device yields a remarkable areal energy density of 99.57 μWh/cm2 at a power density of 387.5 μW/cm2 while retaining approximately ∼ 87.6 % of its initial capacitance after prolonged use. Furthermore, we successfully powered a portable game machine for more than 2 min using two SSCs connected in series with ease. Therefore, this work presents a universal strategy that utilises combination and coating to boost electrochemical performance for flexible high-performance supercapacitors.

PAM/CNTs-Au microcrack sensor with high sensitivity and wide detection range for multi-scale human motion detection

As the quintessential material for flexible sensors, conductive hydrogels face an inherent sensitivity-sensing range paradox and electrical-mechanical balance, which significantly curtail its applicability in multiscale motion detection. Inspired by the spider slit sensor, PAM/CNTs-Au hydrogel microcrack sensor is obtained by depositing conductive gold film on the surface of PAM/CNTs hydrogel using magnetron sputtering. By modulating the cross-linking density of conductive hydrogels and the content of carbon nanotubes (CNTs), it is possible to tailor the mechanical properties and adhesion of PAM/CNTs-Au hydrogel crack-based sensors. This self-adhering flexible sensor aids in minimizing detection errors arising from mechanical mismatch between flexible sensors and human tissues. Moreover, the exceptional electrical conductivity of CNTs, coupled with their unique one-dimensional structure, facilitates the formation of an interconnected conductive network "bridge" within the hydrogel. The harmonization of electrical and mechanical attributes in the PAM/CNTs flexible substrate is achieved by finely tuning the crosslinking density of the PAM hydrogel and the content of carbon CNTs. Simultaneously, the high-conductivity "islands" formed by the Au conductive layer during stretching ensures elevated sensitivity (gauge factor (GF) = 54.89) over an extensive detection range (>1200%). The distinctive "island-bridge" configuration of the PAM/CNTs-Au hydrogel microcrack sensor effectively suppresses crack propagation, thereby markedly augmenting the sensor's stability. Successful monitoring of physiological and motion signals across various scales attests to the potential of the PAM/CNTs-Au hydrogel microcrack sensor in wearable biosensor.

Biomimetics‐Inspired Architecture Enables the Strength–Toughness of Ultrahigh‐Loading Silicon Electrode

AbstractSilicon (Si), as one of the most promising anode candidates, is expected to improve the energy density of Li−ion batteries due to its high specific capacity (≈4200 mAh g−1). However, the cyclic performance of Si anode is unsatisfactory for practical usage due to its inadequate toughness when exceeding the mass loading beyond 2 mg cm−2, which triggers unceasing electrode breakage. Here, a biomimetic Si electrode is created by interconnecting vertically aligned graphene oxide sheets with conductive carbon nanotubes (AGO−Si/C). Unlike reported structures, the AGO−Si/C electrode exhibits superior interlaminar toughness owing to its unique crumpling architecture of reversible interlayer slipping. The elastic structure releases the accumulative lithiation stress of Si nanoparticles to address the degraded inactivation. Thus, the AGO−Si/C electrode shows long−lived cycles by toughening the structure, allowing the fabrication of very thick loading (4.1 mg cm−2) with an impressive areal capacity of 10.0 mAh cm−2. This discovery offers an easily scalable method for graphite/Si anode with high areal capacity that exceeds the commercial−level of 5 mAh cm−2.

High stretchable and tough xylan-g-gelatin hydrogel via the synergy of chemical cross-linking and salting out for strain sensors

Stretchable and tough hydrogels have been extensively used in tissue engineering scaffolds and flexible electronics. However, it is still a significant challenge to prepare hydrogels with both tensile strength and toughness by utilizing xylan, which is abundant in nature. Herein, we present a novel hydrogel of carboxymethyl xylan(CMX) graft gelatin (G) and doped with conductive hydroxyl carbon nanotubes (OCNT). CMX and G are combined through amide bonding as well as intermolecular hydrogen bonding to form a semi-interpenetrating hydrogel network. The hydrogel was further subjected to salting-out treatment, which induced the aggregation of the CMX-g-G molecular chain and the formation of chain bundles to toughen the hydrogel, the tensile strain, tensile stress, and toughness of CMX-g-G hydrogels were 1.547 MPa, 324 %, and 2.31 MJ m−3, respectively. In addition, OCNT was used as a conductive filler to impart electrical conductivity and further improve the mechanical properties of CMX-g-G/OCNT hydrogel, and a tensile strength of 1.62 MPa was obtained. Thus, the synthesized CMX-g-G/OCNT hydrogel can be used as a reliable and sensitive strain sensor for monitoring human activity. This study opens up new horizons for the preparation of xylan-based high-performance hydrogels.

3D Porous Sponge/Carbon Nanotube/Polyaniline/Chitosan Capacitive Bioanode Material for Improving the Power Generation and Energy Storage Performance of Microbial Fuel Cells

Anode materials play a crucial role in the performance of microbial fuel cells (MFCs) in terms of power output. In this study, carbon nanotube (CNT)/polyaniline (PANI)/chitosan (CS) composites were prepared on a porous sponge matrix. The high electrical conductivity of CNTs, the capacitive behavior of PANI, and the biocompatibility of CS were leveraged to enhance the electricity generation and energy storage capabilities of MFCs. Experimental results demonstrated that the MFC with the modified anode achieved a maximum power density of 7902.4 mW/m3. Moreover, in the charging–discharging test, the stored electricity of the S/CNT/PANI/CS anode was 16.38 times that of the S/CNT anode when both the charging and discharging times were 30 min. High-throughput sequencing revealed that the modified composite anode exhibited remarkable biocompatibility and selective enrichment of electrogenic bacteria. Overall, this study presents a novel approach for developing composite MFC anode materials with energy storage functionality.

Scalable and Multifunctional Polyurethane/MXene/Carbon Nanotube-Based Fabric Sensor toward Baby Healthcare.

Continuous monitoring of physiological health status and effective protection against external hazards is an indispensable aspect of healthcare management for critically vulnerable populations, particularly for infants or babies. So, the exploration of all-in-one devices remains critical to avoiding their injury and illness. The integration of multiple properties such as sensing, electromagnetic protection, warming/cooling, and water/bacterial repellence into a common fabric is no doubt a promising solution to coping with diverse application scenarios. However, achieving simultaneous integration in an effective and durable fashion faces huge challenges. Herein, multifunctional fabric was achieved by sequentially coating MXene, carbon nanotubes (CNTs), and self-healing polyurethane (PU) onto cotton fabric. The outstanding conductivity of MXene and CNTs as well as the self-healing ability of PU synergistically enable a flexible, breathable, protective, and sensing fabric with a good durability. It could detect the body motions like bending of the finger, elbow, wrist, and knee, with a high gauge factor of 8.78 and fast response. Moreover, this sensing fabric could protect the wearers against electromagnetic waves and bacteria, delivering a minimum reflection loss of -57.6 dB at 7.6 GHz and high bacterial inhibition efficiency due to the incorporation of MXene and polyethylenimine. Besides, the electrothermal performance of carbonaceous materials enables them to act as a heater for body warmth. The synergistic design of this multifunctional textile offers a promising strategy for producing advanced smart textiles, holding great promise in infant or baby healthcare.

Exploration of electrochemical energy storage potential of PANI functionalized CNTs/Zn-Co(PO4)2 nanocomposites synthesized via a facile ultrasounds-assisted chemical method

Electrochemical performance of supercapacitors (SCs) is greatly affected by different factors like cyclic stability, exposed surface area, rate capability and electrical conductivity. Highly conductive carbon nanotubes (CNTs) functionalized with pseudocapacitive polyaniline (PANI) via in-situ polymerization can intrude conductivity, cyclic stability when used in combination with zinc cobalt phosphate (ZCP). So, in this study, Zn0.25 Co0.75 (PO4)2-PANI/CNTs nanocomposites have been synthesized by sonochemical approach. The hierarchical morphology of the nanocomposite has been evaluated by scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). Whereas the compositional analysis and chemical grafting of ZCP on PANI/CNTs were analyzed by EDX, XRD, and FT-IR spectroscopy. Zn0.25Co0.75 (PO4)2–40 mg PANI/CNTs (ZCP40) outperformed among all compositions and presented good specific capacity of 776 Cg−1 (1410.9 Fg−1) at 0.8 Ag −1 current density. Representative asymmetric supercapacitor (ASC) device of ZCP40//AC presented excellent energy density of 88.5 Wh Kg−1 at an exceptional power density of 900 W Kg−1. Furthermore, device showed good cyclic behavior (99.7 % after 5000 GCD cycles) and, excellent coulombic efficiency (100.11 %) even after 5000 GCD cycles. Overall, the device showed hybrid behavior (72.3 % diffusive and 27.7 % capacitive) due to the highly pseudocapacitive nature of ZCP, PANI and, effective conductive nature of carbon nanotubes (CNTs). Hence ZCP/PANI functionalized CNTs nanocomposites has shown very good potential to be used as +ve electrode material in energy storage devices.

Piezo-tribo-electric nanogenerator based on BCZT/MCNTs/PDMS piezoelectric composite for compressive energy harvesting

BackgroundThis work has developed a novel piezo-tribo-electric nanogenerator (P-TENG) that is capable of converting mechanical energy into electrical energy when operating in compressive mode. MethodsAn arch-shaped P-TENG device was formed using an optimal piezoelectric polymer composite, which was fabricated using a polydimethylsiloxane (PDMS) matrix that was modified with piezoelectric (Ba0.85Ca0.15) (Ti0.90Zr0.10)O3 (BCZT) ceramic particles and electrically conductive multi-walled carbon nanotubes (MCNTs). A high filler loading of BCZT (40, 50, 60 wt%) and 3 wt% of MCNTs was formed into a 0–3 connectivity composite. ResultsThe P-TENG device containing 50 wt% BCZT exhibited the highest electrical output (VOC ∼ 39.7 V, ISC ∼ 1.9 µA, and maximum power ∼ 157.7 µW), compared to the other composites, when subjected to an alternating compressive load of 500 N at a 1 Hz frequency. ConclusionsThis research provides new composite formulations for elastomeric-based energy generators that are responsive to low frequency mechanical oscillations.