PPy Nanowires Research Articles

Fiber organic electrochemical transistors based on multi-walled carbon nanotube and polypyrrole composites for noninvasive lactate sensing.

Multi-walled carbon nanotubes (MWCNT) play a synergistic role with conducting polymer in practical applications such as biological sensing. In this paper, multi-walled carbon nanotube and polypyrrole (PPy) composites were prepared on a fiber surface for the first time, and their morphology and electrical properties were characterized. Compared with PPy-coated fiber, the presence of carbon nanotubes induced the growth of large areas of PPy nanowires. In addition, fiber organic electrochemical transistors (FECTs) based on PPy and MWCNT were assembled, showing a higher on/off ratio, better stability, and greater flexibility. The lactate biosensor based on FECTs exhibits high sensitivity, with a correlation coefficient of R = 0.9889, quick response time of 0.6-0.8s, a wide linear response range of 1nM-1mM, and excellent selectivity for lactate. Furthermore, the lactate concentration in human sweat was successfully detected by a FECT-based sensor. The hybrid fibers can be easily woven and placed on fabric simply by stitching. This favorable performance of the FECT-based sensor makes it suitable for noninvasive sensing of lactate. Therefore, it provides a promising platform for future use in healthcare and detection applications. Graphical abstract.

Engineering nano-heterostructured electrodes based on polypyrrole nanowires@Ni3S2 nanosheets and MoO2 nanoparticles-decorated N-doped carbon nanotubes towards high-performance solid-state asymmetric supercapacitors

Here, polypyrrole@Ni3S2 (PPy@Ni3S2) core-shell nano-heterostructures (CSNHs) as the positive electrode are engineered by electrochemically depositing Ni3S2 nanosheets on the surface of PPy nanowires that are directly electrochemically polymerized on Ni foam. Meanwhile, N-doped carbon nanotubes (N-CNTs)/MoO2 nano-heterostructures (NHs) as the negative electrode are also built by tightly anchoring MoO2 nanoparticles on the surface of N-CNTs through a C–O–Mo bridge. By promoting the surface Faradaic reaction kinetics that are contributed by these two engineered NHs, PPy@Ni3S2 positive electrode demonstrates improved electrochemical performances, i.e., 1841 (1307) F g−1 at 3 (30) A g−1 and 93% capacitance retention over 5000 cycles at 15 A g−1. Likewise, N-CNTs/MoO2 negative electrode also exhibits a specific capacitance of up to 489 F g−1 at 1 A g−1, 69% capacitance retention at 20 A g−1 as well as 95% capacitance retention after 5000 cycles at 10 A g−1. Moreover, the assembled PPy@Ni3S2//N-CNTs/MoO2 solid-state asymmetric supercapacitors (ASCs) device delivers an energy density of 71.5 Wh kg−1 at a power density of 801 W kg−1. These results may give insights into the great promise of engineering NHs electrodes based on conductive polymers/metal sulfides and carbon/metal oxides towards high-performance energy storage devices.

Ternary thermoelectric composites of polypyrrole/PEDOT:PSS/carbon nanotube with unique layered structure prepared by one-dimensional polymer nanostructure as template

Recently, organic polymer-based thermoelectric (TE) hybrids or composites have received significant attention. Here, a unique layered morphology of polypyrrole/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)/single-walled carbon nanotube (PPy/PEDOT:PSS/SWCNT) ternary TE composites are designed using 1D nanostruture of PPy as template. The nanowires of PPy/PEDOT:PSS binary composites are obtained via coating PEDOT:PSS on the surfaces of 1D PPy nanowires. Interestingly, the PPy/PEDOT:PSS/SWCNT ternary composites reveal unexpected layered morphology and dramatically-enhanced TE function with an optimal power factor of 45.3 ± 1.4 μW m−1 K−2 at room temperature. This study will enrich the structure design and preparation strategy of novel TE composites by judicious combing 1D polymer nanostructure with 3D layered networks of composites.

Sensitive and selective detection of Pb (II) and Cu (II) using a metal-organic framework/polypyrrole nanocomposite functionalized electrode

An electrochemical sensor based on a NH2-MIL-53(Al)/polypyrrole (PPy) nanocomposite modified gold electrode for determination of ultra-trace Pb (II) and Cu (II) was developed. The PPy nanowires were synthesized through a chemical polymerization process, and the NH2-MIL-53(Al) was deposited on the PPy nanosubstrates by an in-situ electrochemical method. Field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) spectroscopy and attenuated total reflection infrared (ATR-IR) spectroscopy were used to study the structural features of the nanocomposite. The electrochemical behavior of the NH2-MIL-53(Al)/PPy nanocomposite toward Pb (II) and Cu (II) was investigated by differential pulse voltammetry (DPV) technique. Due to the synergistic effect of the PPy and NH2-MIL-53(Al), the nanocomposite modified electrode exhibited good sensing performance to Pb (II) and Cu (II) in the range of 1–400 μg L−1 with detection limit of 0.315 μg L−1 and 0.244 μg L−1, respectively. The limit of detection and the sensitivity of the NH2-MIL-53(Al)/PPy nanocomposite modified electrode were significantly enhanced than those of the individual modified electrodes. The effective electrochemical property of the nanomaterial for the Pb (II) and Cu (II) could provide a new direction for the heavy metal ions determination.

Nano patterning and fabrication of single polypyrrole nanowires by electron beam lithography

In this paper, fabrication of nanostructures of conducting polypyrrole (PPy) thin films on the surfaces by in situ chemical polymerization in the presence of different anionic dopants including anthraquinone-2-sulfonic acid sodium salt monohydrate/5-sulfosalicylic acid dehydrate (AQSANa/SSCA) and camphor sulfonic acid (CSA) is reported. “Lift-off process” combined with electron beam lithography (EBL) is used for fabrication of nano patterns of conducting PPy thin films down to 100 nm. In addition, the ability to create ordered single PPy nanowires of controlled dimension, with very high aspect ratio, and dendrite free features between Au electrodes for fabricating of field effect transistor (FET) was demonstrated by single wires of PPy-CSA and PPy-(AQSANa,SSCA) with 250 nm widths, up to 12 μm lengths and 100 nm thickness. I–V measurements of both single PPy-CSA (˜ 124 S/cm) and PPy-(AQSANa,SSCA) (˜ 5 S/cm) nanowires indicated Ohmic or space charge limited conduction, depending on the applied bias on the contact electrodes. A considerable modulation in the electrical conductivity of PPy-CSA and PPy-(AQSANa,SSCA) nanowire p-FETs was demonstrated as a result of varying the gate potential. Both PPy-CSA and PPy-(AQSANa,SSCA) nanowire p-FETs provide good performance transistors, nevertheless show different device electrical characteristics due to used different anionic dopants.

S@TiO2 nanospheres loaded on PPy matrix for enhanced lithium-sulfur batteries

The development of lithium-sulfur batteries has been impeded by the shuttle effect and insulation of sulfur cathodes so far. Here we report a novel cathode consisting of a sulfur@TiO2/polypyrrole (S@TiO2/PPy) composite, in which sulfur is encapsulated by TiO2 hollow spheres and then loaded on a PPy nanowire matrix together. The S@TiO2/PPy cathodes for lithium-sulfur batteries deliver an excellent electrochemical performance with a high initial specific capacity of 1385.9 mAh g−1 at 0.2 C and a low decay rate of 0.047 % per cycle at 1 C. The enhanced property of S@TiO2/PPy composites maybe derived from a synergistic reaction on sulfur between TiO2 hollow spheres and conductive polypyrrole nanowires, which plays a vital role on inhibiting the shuttle effect and improving the conductivity of sulfur cathodes through encapsulating sulfur active materials, chemical adsorbing polysulfides and mixing the conductive component. The architectural design on S@TiO2/PPy cathodes will provide a promising route for the practical usage of lithium-sulfur batteries.

Morphologies Tuning of Polypyrrole and Thermoelectric Properties of Polypyrrole Nanowire/Graphene Composites.

Polypyrrole (PPy) with different morphologies (e.g., particles, nanotubes, and nanowires) were successfully prepared by adding or without adding different kinds of surfactants through a chemical oxidative polymerization method, respectively. The results show that the morphologies of PPy can be effectively controlled and have a significantly effects on their thermoelectric properties. The PPy nanowires exhibit the highest electrical conductivity and Seebeck coefficient among the various PPy morphologies, such as particles, nanotubes, and nanowires, so PPy nanowires were chosen to prepare PPy nanowire/graphene thermoelectric composites via a soft template polymerization method using cetyltrimethyl ammonium bromide as the template. Both electrical conductivity and Seebeck coefficient of the PPy nanowire/graphene composites increased as the content of graphene increases from 0 to 20 wt %, and as the measured temperature increases from 300 K to 380 K, which leds to the same trend for the power factor. A highest power factor of 1.01 μWm−1K−2 at ~380 K was obtained for the PPy nanowire/graphene composites with 20 wt % PPy nanowire, which is about 3.3 times higher than that of the pure PPy nanowire.

A Conductive Nanowire‐Mesh Biosensor for Ultrasensitive Detection of Serum C‐Reactive Protein in Melanoma

AbstractDetection of extracutaneous melanoma is still challenging and is of importance in improving survival rate. In this report, an ultrasensitive biosensor is constructed where a C‐reactive protein (CRP) aptamers based molecular recognition core and a conductive polypyrrole (PPy) nanowire mesh based signal amplifier are developed. The conductive PPy nanowire (less than 10 nm in diameter) mesh architecture is uniformly dispersed within polymeric matrix via template‐free in situ synthesis. Serum CRP levels are quantitatively analyzed through monitoring the conductance change caused by polymeric network shrinkage upon the aptamer‐CRP binding. The limit of detection (LOD) of the polymeric sensor for human CRP sample can reach 7.85 × 10−19m. This CRP‐specific biosensor and a commercial CRP enzyme‐linked immunosorbent assay (ELISA) kit are used to perform side‐by‐side measurement of serum CRP in melanoma patients. The results indicate that this conductive polymeric senor is highly sensitive and selective in accurately discriminating melanoma patients from healthy controls using serum CRP as a biomarker, which is further validated by a commercial human CRP ELISA kit. Collectively, this novel ultrasensitive nanowire‐based polymeric biosensor may hold promise in biomarker detection and diagnosis of cancer.

Direct Observation of Plasmon-Induced Interfacial Charge Separation in Metal/Semiconductor Hybrid Nanostructures by Measuring Surface Potentials.

Plasmon-induced interfacial charge separation (PICS) is one of the key processes responsible for the improved conversion efficiencies of energy-harvesting devices that incorporate metal nanostructures. In this Letter, we reveal a mechanism of PICS by visualizing (with nanometer-scale resolution) and characterizing plasmon-exciton coupling between p-type poly(pyrrole) (PPy) nanowires (NWs) and Ag nanoparticles (NPs) using light-irradiated Kelvin probe force microscopy (KPFM). Under blue-light irradiation, the Ag NPs are expected to donate electrons to the PPy NWs via a hot electron injection process. However, in this Letter, we observe that under blue-light irradiation the plasmonically and excitonically excited electrons in the semiconductor back-transfer to the metal. The PICS in this system can be explained by comparing it with a similar one where Au NPs are attached to n-type ZnO NWs; we observed a net electron transfer from the Au NPs to the ZnO NWs (an upward band bending is formed at the interface of the two materials, presumably obstructing electron back-transfer). Indeed, energy band matching between the metal and the semiconductor components of hybrid nanostructures influences PICS pathways. These experimental findings and our proposed mechanism consistently explain the PICS occurring in the PPy NW-Ag NP system with important implications on explaining their cooperative optoelectronic activities.

Polypyrrole nanowires coated with a hollow shell for enhanced electrochemical performance

Conducting polymers are promising electrode materials for electrochemical capacitors, but are suffered from poor cycling stability and relatively low capacitance. Herein, a hollow shell coated on polypyrrole (Ppy) nanowires is designed and constructed with the assistance of atomic layer deposition (ALD). Ppy nanowires are firstly deposited on flexible carbon cloth by electrodeposition, then a thin sacrificial layer of ZnO and a thin shell of TiO2 are deposited uniformly on the surfaces of the nanowires. After removing the ZnO layer, a nanogap between the Ppy core and TiO2 shell is formed thus generate a hollow core-shell Ppy-TiO2 (noted as PpyʘTiO2) nanoarray. When tested as supercapacitor electrodes, the hollow core-shell nanostructure shows apparent higher capacitance and better cycling stability than the bare nanowires. Such enhancement is ascribed to the rational hollow structure design that provides enlarged surface areas and enhanced structure stability. Such hollow structure can be extended to other conducting polymers and electrodes for various electrochemical applications.

Highly Stretchable, Compliant, Polymeric Microelectrode Arrays for In Vivo Electrophysiological Interfacing.

Polymeric microelectrode arrays (MEAs) are emerging as a new generation of biointegrated microelectrodes to transduce original electrochemical signals in living tissues to external electrical circuits, and vice versa. So far, the challenge of stretchable polymeric MEAs lies in the competition between high stretchability and good electrode-substrate adhesion. The larger the stretchability, the easier the delamination of electrodes from the substrate due to the mismatch in their Young's modulus. In this work, polypyrrole (PPy) electrode materials are designed, with PPy nanowires integrated on the high conductive PPy electrode arrays. By utilizing this electrode material, for the first time, stretchable polymeric MEAs are fabricated with both high stretchability (≈100%) and good electrode-substrate adhesion (1.9 MPa). In addition, low Young's modulus (450 kPa), excellent recycling stability (10 000 cycles of stretch), and high conductivity of the MEAs are also achieved. As a proof of concept, the as-prepared polymeric MEAs are successfully used for conformally recording the electrocorticograph signals from rats in normal and epileptic states, respectively. Further, these polymeric MEAs are also successful in stimulating the ischiadic nerve of the rat. This strategy provides a new perspective to the highly stretchable and mechanically stable polymeric MEAs, which are vital for compliant neural electrodes.

Annealing led conversion from polypyrrole to carbon nitride nanowires and the fabrication of highly efficient ammonia sensing device

In this work, first of all, polypyrrole (PPy) nanowires have been successfully prepared using template synthesis technique at room temperature by chemical polymerisation of pyrrole within the pores of anodic alumina template. Secondly, the effect of 4 h annealing on morphological, optical and ammonia gas sensing device properties has been studied at 200 °C and 300 °C. The characterization of unanealed and annealed samples was done by using scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and time resolved photoluminescence. IV measurements are done for studying gas sensing device. The SEM confirms the flexible wire-like morphology of unannealed and annealed nanowires whereas XRD investigation shows the amorphous nature of unannealed and annealed nanowires. Characteristic peaks of FTIR confirm the formation of PPy nanowires synthesized at room temperature and transition from polypyrrole to carbon nitride nanowires after annealing PPy nanowires at 200 and 300 °C. The transition from PPy to CNx nanowires after annealing is proved by the characteristic FTIR peaks corresponding to C=C and C=N bond and the time resolved photoluminescence spectra recorded at different wavelengths corresponding to polypyrrole and carbon nitride well known transitions. I–V studies of nanowires show the increase in sensitivity of annealed nanowires towards NH3 at about thousand times than that of unannealed nanowires.

In Situ Growth of Polypyrrole onto Three-Dimensional Tubular MoS2 as an Advanced Negative Electrode Material for Supercapacitor

In this work, three-dimensional (3D) tubular molybdenum disulfide (MoS2)/PPy composites have been prepared, in which the MoS2 is as the framework to promote the insertion and extraction of electrolyte ions, and PPy spherical particles or nanowires are synthesized by an in-situ oxidative polymerization method in the presence of the MoS2. FT-IR, XRD, XPS, FESEM and HRTEM are used to characterize the structures and morphologies of the as-prepared materials. The combination of conductive PPy and 3D tubular MoS2 leads to a significant synergistic effect. For MoS2/PPy particle composites, the best performance (specific capacitance of 350F/g at a current density of 1A/g) is obtained from a sample prepared with the mass ratio of pyrrole to MoS2 being 2:1. While for MoS2/PPy nanowire composites, the best performance (specific capacitance of 462F/g at 1A/g and a good cycling stability of 82% after 2000 cycles at 3A/g) is obtained from a sample prepared with the mass ratio of pyrrole to MoS2 being 5:1, which shows much better supercapacitor performance than the MoS2/PPy composite. Moreover, the composite electrode material delivers an energy density as high as 25.5 Wh/kg at a power density of 266.3W/kg and maintains 14.5 Wh/kg at a high power density of 4002W/kg. These performances feature the composite as advanced negative electrode materials and are superior to previous reports.

Electrodeposition of gold nanoparticles decorated single polypyrrole nanowire for arsenic detection in potable water: a chemiresistive sensor device

Electrodeposition of gold nanoparticles (Au-NPs) decorated single polypyrrole nanowire (Ppy-NW) for arsenic (As) detection was studied in this paper. Arsenic is a toxic element, which exists in variety of chemical forms. Arsenic forms combined with groundwater and soil is leading to toxicity and creating health risks, hence the requirement of its detection arises. The present study is to develop a highly sensitive Au-NPs decorated Ppy-NW based sensor for detecting the trace amounts of arsenic (As3+). The chemiresistive method was adopted for detecting the sensitivity of the arsenic traces. A 200 nm in diameter Ppy nanowires were developed using anodic aluminum oxide (AAO) template based synthesis and decorated with Au-NPs and further tested for arsenic sensing. The response of arsenic with the sensors was recorded by chemiresistive method with varying potential between ±100 mV. The sensitivity of Au-NPs decorated Ppy-NW towards arsenic (for two set of As conc. range) was observed to be 0.22 and 4.38 µM−1 and the detection limit of the sensor was observed to be 0.32 µM

Electromagnetic wave absorption property of polypyrrole nanowires/graphene composite

We develop a facile low-temperature polymerization method for fabricating a PPy/G composite that can be used as a lightweight EMW absorber. Scanning electron microscopy image shows that the length of PPy nanowirs is several micrometers, and the well-defined interfaces between graphene and PPy nanowires. All of the reflection loss values for the composite at d ranging from 2.0 to 5.0 mm are less than −20 dB. For example, the minimal reflection loss is –38.9 dB as the thickness of the composite 3.0 mm at 11.28 GHz; the minimal reflection loss is –39.1 dB as the thickness of the composite 3.5 mm at 9.36 GHz, outperforming PPy nanowires and graphene-based absorbers reported previously. Furthermore, the content of the PPy/G composite in the paraffin matrix is only 5 wt%, greatly lower than that of PPy nanowires and graphene-based absorbers reported previously. The enhanced electromagnetic wave absorption property can be explained by interfacial polarization and 1/4 quarter-wavelength matching model. Our results may open a way to the development of highly lightweight EMW absorbers.

Combination of Fe-Mn based Li-rich cathode materials and conducting-polymer polypyrrole nanowires with high rate capability

The polypyrrole (PPy) nanowires are conducting 1D materials, which can significantly improve the electrical conductivity of the composites. A novel Li1.26Fe0.22Mn0.52O2 (LFMO) @ PPy nanowire composites were synthesized by simply ultrasonic dispersing LFMO and PPy nanowires in aqueous ethanol. The structure and morphology of pristine LFMO and LFMO@PPy are investigated by XRD, SEM, and TEM. The elemental mapping and FTIR results demonstrate the conductive network of PPy nanowires exists in the composites and the LFMO particles uniformly distribute on the PPy nanowires. LFMO combined with PPy nanowires exhibits better rate capability, higher capacity, coulombic efficiency, and cycleability than the pristine. The rate performance of composites with 10 wt% PPy nanowires shows the discharge capacities of 132.2 mAh/g and 98 mAh/g at 1C and 3C rate after 50 cycles, respectively. Electrochemical impedance spectroscopy test suggests that the conductive PPy nanowires can significantly decrease the charge-transfer resistance of LFMO. The composite with 10 wt% PPy nanowires shows a discharge capacity retention of 71% after 50 cycles at 1C, while the pristine sample only has 50% capacity retention.

The woven fiber organic electrochemical transistors based on polypyrrole nanowires/reduced graphene oxide composites for glucose sensing

Novel woven fiber organic electrochemical transistors based on polypyrrole (PPy) nanowires and reduced graphene oxide (rGO) have been prepared. SEM revealed that the introduction of rGO nanosheets could induce the growth and increase the amount of PPy nanowires. Moreover, it could enhance the electrical performance of fiber transistors. The hybrid transistors showed high on/off ratio of 102, fast switch speed, and long cycling stability. The glucose sensors based on the fiber organic electrochemical transistors have also been investigated, which exhibited outstanding sensitivity, as high as 0.773 NCR/decade, with a response time as fast as 0.5s, a linear range of 1nM to 5μM, a low detection concentration as well as good repeatability. In addition, the glucose could be selectively detected in the presence of ascorbic acid and uric acid interferences. The reliability of the proposed glucose sensor was evaluated in real samples of rabbit blood. All the results indicate that the novel fiber transistors pave the way for portable and wearable electronics devices, which have a promising future for healthcare and biological applications.

Flexible and high energy density asymmetrical supercapacitors based on core/shell conducting polymer nanowires/manganese dioxide nanoflakes

Hierarchically porous polypyrrole nanowires/manganese oxides nanoflakes (MnO2 NFs@PPy NWs) core/shell nanostructures were successfully constructed through a simple, convenient and environmentally friendly method by using PPy nanowires as the core buffer and K-Birnessite type MnO2 as the shell. The core/shell nanostructures effectively increase active surface areas and decrease the ion transmission distance, which is conducive to the efficient transfer of ions. The MnO2 NFs@PPy NWs core/shell nanostructures exhibited not only high specific capacitance (276Fg−1 at 2Ag−1) but also excellent capacitance retained ratio of 72.5% under extreme charge/discharge conditions (200Fg−1 at 20Ag−1) due to the synergistic effect by combining the merits of MnO2 and PPy. Using such hierarchical nanostructure as the positive electrode, we further demonstrate that ultra-flexible asymmetrical supercapacitors (AFSCs) (MnO2@PPy//AC) possess excellent cycling stability (90.3% after 6000 cycles at 3Ag −1), mechanical flexibility, large voltage operation window (1.8–2.0V vs. SCE) and high energy densities at all charge/discharge conditions (25.8Whkg−1 at the power density of 901.7Wkg−1, and 17.1Whkg−1 at the power density of 9000Wkg−1, respectively).

Well-dispersed sulfur anchored on interconnected polypyrrole nanofiber network as high performance cathode for lithium-sulfur batteries

Preparation of novel sulfur/polypyrrole (S/PPy) composite consisting well-dispersed sulfur particles anchored on interconnected PPy nanowire network was demonstrated. In such hybrid structure, the as-prepared PPy clearly displays a three-dimensionally cross-linked and hierarchical porous structure, which was utilized in the composite cathode as a conductive network trapping soluble polysulfide intermediates and enhancing the overall electrochemical performance of the system. Benefiting from this unique structure, the S/PPy composite demonstrated excellent cycling stability, resulting in a discharge capacity of 931 mAh g−1 at the second cycle and retained about 54% of this value over 100 cycles at 0.1 C. Furthermore, the S/PPy composite cathode exhibits a good rate capability with a discharge capacity of 584 mAh g−1 at 1 C.

Combination and High Rate Capability of Fe-Mn Based Li-Rich Cathode Materials with Conducting-Polymer Polypyrrole Nanowires

The Lithium-rich solid solutions between layer-structured Li2MnO3 and LiMO2 (M=Ni、Co、Fe) are attractive cathode materials for lithium ion batteries with high specific energy densities. Among them, the Fe-Mn based Li-rich cathode materials Li1+x(FeyMn1-y)1-xO2 are the most potential candidates with high theoretical capacity [1] and low cost, because Fe element is much more inexpensive and abundant compared to Ni and Co. However, there are several drawbacks in the Fe-Mn based materials, such as the disorder of Li and Fe atoms impedes the migration of Li+ and worsen the electrochemical performance [2], and the Li2MnO3 component with worse conductivity leads to poor rate property. To overcome these shortcomings, nano crystalline Fe-Mn based Li-rich materials are suggested, and conductive polymer webs also are introduced to combine with the nano particles of active materials, which could improve their rate capability by reducing the lithium ion diffusion length [3]and conductive network formation. Polypyrrole (PPy), a typical soft conducting polymer with good mechanical exibility and chemical stability during the electrochemical process, has been attracted much attention. PPy also can act as a host material for Li+ ion insertion/extraction in the voltage range of 2.0-4.5 V versus Li/Li+, with a theoretical capacity of 72 mAh g-1 [4, 5]. Therefore, polypyrrole not only can improve conductivity between Li1.26Fe0.22Mn0.52O2 particles, but also exhibit extra electrochemical activity as cathode material. In this work, polypyrrole nanowires used as a conductive network were synthesized by a modified oxidative template assembly route, as shown in Fig. 1 (a). Li-rich layered oxide cathode Li1.26Fe0.22Mn0.52O2 (LFMO) is synthesized via a low temperature molten salt method. The composite of LFMO with PPy nanowires content of 10wt% was prepared as following: LFMO powder was added into ethanol and distilled water (Volume=1:1) in an ultrasonic bath for 30min to obtain the suspension A, then as-prepared PPy nanowires were dispersed in ethanol in an ultrasonic bath for 20min to obtain the suspension B. After an additional 1h holding period in the ultrasonic bath, suspension A and B were mixed under continuous stirring for 24h. The final composite powders were filtered, washed and dried at 60°C in a vacuum oven, then heated at 100°C for 2h. The obtained Li1.26Fe0.22Mn0.52O2sample is combined with PPy nanowires about 10% mass ratio, labelled as LFMO/PPy. As shown in Fig.1, the morphologies of PPy nanowires and LFMO/PPy composite are characterized by Transmission electron microscope (TEM). The fiber diameter of PPy nanowires used as three-dimensional network is approximate 90 nm, seen from Fig. 1 (a). The Fig. 1 (b) demonstrates that nano LFMO particles are indeed adhereing to the PPy nanowires, and the PPy matrix can reduce the particle-to-particle contact resistance, improving the electrical conductivity of the composite. The rate performance of LFMO/PPy is shown in Fig. 1(c) and (d). It is clearly that the cycle performance with different rate ratios of LFMO is greatly enhanced by combining with PPy nanowires. The capacities of LFMO/PPy composite is stable at 132.2mAh g-1 at 1C and 98 mAh g-1 at 3C after 50cycles respectively, which is about 50-30 mAh g-1higher than those of the pristine. The excellent rate capability is mainly due to greatly increasing the electrode conductivity via the conducting-network of PPy nanowires, which also ensured higher discharge plateau voltage even at 3C. And more test results show that the existing of PPy conductive network improves the initial coulombic efficiency and the cycling stability of LFMO material.