Preparation and Characterization of NiO/YSZ Cathode and BSCF/SDC Anode of SOEC for Hydrogen Production

In this paper, NiO-YSZ composite powder was synthesized via in situ urea combustion method to prepare high homogeneity cathode. Sm0.2Ce0.8O1.9(SDC) is used as a barrier interlayer between Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) anode and 8YSZ electrolyte to avoid solid state interaction for high temperature application. The crystal structure and surface morphologies of NiO, YSZ, BSCF and SDC powders were characterized, respectively. The optimization of technological conditions for the synthesis was investigated. The adding amount was calculated by the combustion reaction equation. BSCF-SDC/YSZ/Ni-YSZ single button cells were prepared and the related electrochemical performances were test at 850°C. The research results showed that the products were well crystallized with NiO coating on YSZ particles. The optimized addition of CO(NH2)2to Ni(NO3)2was 2:1. A SOEC single cell made from NiO-YSZ with the molar ratio of 2:1 composite powder exhibited better performance than the other samples with the electrolytic voltage of 0.98V and showed excellent durability under the electrolytic currency of 0.33 A/cm2, the input stream of 90%H2O+10%H2. The hydrogen production rate of the single SOEC using BSCF/SDC can be up to 196.6 mL·cm-2h-1, which indicates that it could be a potential candidate for the future application of SOEC technology.

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Synthesis of SiCW/(Mo,W)Si2 Composite by the "Chemical Oven" Self-Propagating Combustion Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.368-372.951 ◽

2008 ◽

Vol 368-372 ◽

pp. 951-954 ◽

Cited By ~ 1

Author(s):

Jian Guang Xu ◽

Hou An Zhang ◽

Guo Jian Jiang ◽

Wen Lan Li

Keyword(s):

Solid Solution ◽

Flexural Strength ◽

Room Temperature ◽

Composite Powder ◽

Cost Effective ◽

Combustion Method ◽

Sintering Process ◽

High Temperature Synthesis ◽

Result Show

SiC whisker reinforced (Mo,W)Si2 composite powder has been successfully synthesized by a novel process, named as chemical oven self-propagating high temperature synthesis (COSHS). The mixtures of Si and Ti powders were ignited as chemical oven. XRD result shows that the combustion product is mainly composed of (Mo,W)Si2 solid solution and SiC phases. SEM photo and EDS result show that SiC whisker is formed during this process. The as-prepared SiCW/(Mo,W)Si2 composite powder has been pressureless sintered. The microstructure and mechanical properties of the composite were investigated. Relative densities of the monolithic material and composite are 91.2% and 92.2%, respectively. The composite containing SiC whisker and (Mo,W)Si2 solid solution has higher Vickers hardness than monolithic MoSi2. Especially the room-temperature flexural strength of the composite is higher than that of monolithic MoSi2, from 135.5MPa for MoSi2 to 235.6MPa for composites with 10 vol.% WSi2 and 15 vol.% SiC, increased by 73.9%. The morphology of fractured surface of composite reveals the mechanism to improve flexural strength of MoSi2. The results of this work show that in situ SiCW/(Mo,W)Si2 composite powder prepared by COSHS technique could be successfully sintered via pressureless sintering process and significant improvement of room temperature flexural strength could be achieved. It could be a cost-effective process for industry in future applications.

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Construction of NiCoZnS materials with controllable morphology for high-performance supercapacitors

Nanotechnology ◽

10.1088/1361-6528/ac4210 ◽

2021 ◽

Author(s):

Zifeng Tian ◽

hongyan zeng ◽

Shi-Bing Lv ◽

YiWen Long ◽

Sheng Xu ◽

...

Keyword(s):

Active Sites ◽

High Performance ◽

Metal Sulfide ◽

Molar Ratio ◽

Electrochemical Performances ◽

Long Cycle Life ◽

Hydrothermal Approach ◽

Mixed Transition ◽

Asymmetric Device

Abstract A facile two-step hydrothermal approach with post-sulfurization treatment was put forward to construct the mixed transition metal sulfide (NiCoZnS) with a high electrochemical performance. The different morphologies of NiCoZnS materials were successfully fabricated by adjusted the Ni/Co molar ratio of the NiCoZn(OH)F precursor. Moreover, the in-situ phase transformation from the NiCoZn(OH)F phase to Zn0.76Co0.24S and NiCo2S4 phases and lattice defects via the S2− ion-exchange were determined by XRD, TEM and XPS techniques, which improved electric conductivity and interfacial active sites of the NiCoZnS, and so promoted the reaction kinetics. Significantly, the urchin-like NiCoZnS1/1 prepared at the Ni/Co molar ratio of 1.0 exhibited promising electrochemical performances with high capacitance and excellent cycling stability. Furthermore, the asymmetric device (NiCoZnS//AC) using NiCoZnS1/1 as the positive electrode had excellent supercapacitor performances with an energy density of 57.8 Wh·kg–1 at a power density of 750 W·kg–1 as well as a long cycle life (79.2% capacity retention after 10000 cycles), indicating the potential application in high-performance supercapacitors.

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Preparation of Polyaniline/FeFe(CN)6 Composite and its Electrochemical Performance as Cathode Material of Lithium Ion Battery

NANO ◽

10.1142/s1793292020501076 ◽

2020 ◽

Vol 15 (08) ◽

pp. 2050107

Author(s):

Lihuan Xu ◽

Yue Sun ◽

Bing Han ◽

Chang Su

Keyword(s):

Lithium Ion Battery ◽

Specific Capacity ◽

Lithium Ion ◽

Electrochemical Performances ◽

Potential Candidate ◽

Face Centered Cubic ◽

In Situ Oxidation ◽

Face Centered ◽

Cycling Performances

In this paper, polyaniline/FeFe(CN)6(PANI-FeFe(CN)6) composites were prepared by a simple in-situ oxidation polymerization in perchloric acid (HClO4) solution in which the obtained polyaniline (PANI) self-assembled to form the tube-like morphology, while FeFe(CN)6 with perfect face-centered cubic lattice (FCC)-type structure was well-dispersed in the obtained PANI matrix. As the cathode of lithium ion battery, PANI-FeFe(CN)6 composite demonstrates the improved specific capacity, cycling stability and current rate performances. For PANI-FeFe(CN)6 composite prepared by feed mass ratio of FeFe(CN)[Formula: see text] Aniline to 80:100 (PANI-FeFe(CN)6(80%)), it still remained 95.7[Formula: see text]mAh/g of discharge capacity after 100 cycles, indicating its excellent cycling performances. Especially, its specific capacities were 95.9, 98.8, 91.4, 83.6 and 72[Formula: see text]mAh/g at the current density of 20, 50, 100, 200 and 500[Formula: see text]mA/g, which were obviously higher than that of PANI or FeFe(CN)6, respectively. The improved thermal stability and electrochemical performances for PANI-FeFe(CN)6 composites could be ascribed to the formed interaction between PANI and FeFe(CN)6 components and the enhanced electrical conductivity, which made it a potential candidate as the cathode of lithium battery.

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In-Situ Annealed Ti3C2Tx MXene Based All-Solid-State Flexible Zn-Ion Hybrid Micro Supercapacitor Array with Enhanced Stability

Nano-Micro Letters ◽

10.1007/s40820-021-00634-2 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

La Li ◽

Weijia Liu ◽

Kai Jiang ◽

Di Chen ◽

Fengyu Qu ◽

...

Keyword(s):

High Energy ◽

High Rate ◽

High Energy Density ◽

Electrochemical Performances ◽

Integrated Electronics ◽

Long Term Stability ◽

Hybrid Supercapacitors ◽

Portable Electronics

AbstractZn-ion hybrid supercapacitors (SCs) are considered as promising energy storage owing to their high energy density compared to traditional SCs. How to realize the miniaturization, patterning, and flexibility of the Zn-ion SCs without affecting the electrochemical performances has special meanings for expanding their applications in wearable integrated electronics. Ti3C2Tx cathode with outstanding conductivity, unique lamellar structure and good mechanical flexibility has been demonstrated tremendous potential in the design of Zn-ion SCs, but achieving long cycling stability and high rate stability is still big challenges. Here, we proposed a facile laser writing approach to fabricate patterned Ti3C2Tx-based Zn-ion micro-supercapacitors (MSCs), followed by the in-situ anneal treatment of the assembled MSCs to improve the long-term stability, which exhibits 80% of the capacitance retention even after 50,000 charge/discharge cycles and superior rate stability. The influence of the cathode thickness on the electrochemical performance of the MSCs is also studied. When the thickness reaches 0.851 µm the maximum areal capacitance of 72.02 mF cm−2 at scan rate of 10 mV s−1, which is 1.77 times higher than that with a thickness of 0.329 µm (35.6 mF cm−2). Moreover, the fabricated Ti3C2Tx based Zn-ion MSCs have excellent flexibility, a digital timer can be driven by the single device even under bending state, a flexible LED displayer of “TiC” logo also can be easily lighted by the MSC arrays under twisting, crimping, and winding conditions, demonstrating the scalable fabrication and application of the fabricated MSCs in portable electronics.

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In-Situ Laser Polishing Additive Manufactured AlSi10Mg: Effect of Laser Polishing Strategy on Surface Morphology, Roughness and Microhardness

Materials ◽

10.3390/ma14020393 ◽

2021 ◽

Vol 14 (2) ◽

pp. 393

Author(s):

Jiantao Zhou ◽

Xu Han ◽

Hui Li ◽

Sheng Liu ◽

Shengnan Shen ◽

...

Keyword(s):

Surface Quality ◽

Molten Pool ◽

Surface Defects ◽

Polished Surface ◽

Transient Model ◽

Surface Evolution ◽

Powder Bed ◽

Laser Polishing ◽

Surface Morphologies

Laser polishing is a widely used technology to improve the surface quality of the products. However, the investigation on the physical mechanism is still lacking. In this paper, the established numerical transient model reveals the rough surface evolution mechanism during laser polishing. Mass transfer driven by Marangoni force, surface tension and gravity appears in the laser-induced molten pool so that the polished surface topography tends to be smoother. The AlSi10Mg samples fabricated by laser-based powder bed fusion were polished at different laser hatching spaces, passes and directions to gain insight into the variation of the surface morphologies, roughness and microhardness in this paper. The experimental results show that after laser polishing, the surface roughness of Ra and Sa of the upper surface can be reduced from 12.5 μm to 3.7 μm and from to 29.3 μm to 8.4 μm, respectively, due to sufficient wetting in the molten pool. The microhardness of the upper surface can be elevated from 112.3 HV to 176.9 HV under the combined influence of the grain refinement, elements distribution change and surface defects elimination. Better surface quality can be gained by decreasing the hatching space, increasing polishing pass or choosing apposite laser direction.

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In situ XRD and operando spectra-electrochemical investigation of tetragonal WO3-x nanowire networks for electrochromic supercapacitors

NPG Asia Materials ◽

10.1038/s41427-021-00319-7 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Shen Wang ◽

Hongbo Xu ◽

Tingting Hao ◽

Peiyuan Wang ◽

Xiang Zhang ◽

...

Keyword(s):

Reaction Mechanism ◽

Electronic Device ◽

High Capacity ◽

Optical Modulation ◽

Function Evaluation ◽

Dual Function ◽

Electrochemical Performances ◽

Electrochemical Cycling ◽

Nanowire Networks

AbstractElectrochromic supercapacitors (ESCs) are appealing for smart electronic device applications due to their advantages of dual-function integration. Unfortunately, the synchronous dual-function evaluation and the essential reaction mechanism are ambiguous. Herein, we constructed a 3D WO3-x nanowire networks/fluorine-doped tin oxide (WO3-x NWNs/FTO) bifunctional electrode for ESCs by a solvothermal self-crystal seeding method. The synchronous correspondence relationship between the optical and electrochemical performances of the WO3-x NWNs/FTO electrode was explored using an operando spectra-electrochemical characterization method. It reveals an excellent areal capacity of 57.57 mF cm−2 with a high corresponding optical modulation (ΔT) of 85.05% and high optical-electrochemical cycling stability. Furthermore, the synergistic reaction mechanism between the Al3+ ion intercalation behavior and the surface pseudocapacitance reaction during electrochemical cycling is revealed utilizing in situ X-ray diffraction. Based on these results, an ESC device was constructed by pairing WO3-x/FTO as the cathode with V2O5 nanoflowers/FTO (V2O5 NFs/FTO) as the anode, which simultaneously deliver high capacity and large optical modulation. Moreover, the energy storage level of the ESC device could be visually monitored by rapid and reversible color transitions in real time. This work provides a promising pathway to developing multi-functional integrated smart supercapacitors.

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