Good Cycle Life Research Articles

Thermal property and failure behaviors of Gd doped LaZrCeO coatings with feathery microstructure

LaZrCeO coatings are promising candidates to substitute Y2O3-stabilized ZrO2 in advanced gas turbine engines. In this study, Gd doped LaZrCeO coatings were deposited by electron beam physical vapor deposition. This study focuses on the phase, microstructure, thermal property, and thermal durability of (La1-xGdx)2(Zr0.7Ce0.3)2O7 coatings. The as-deposited coatings show relatively good thermal shock life and thermal cycling life. The broken regions are observed on the interface of thermal barrier coatings. The failure behaviors are relevant with crack evolution and thermally grown oxide growth. This study might guide the investigation of advanced coatings under high temperature.

Co-induced performance optimization of Fe-based coordination polymers for lithium storage

As electrode for lithium ion batteries (LIBs), Coordination polymers (CPs) have exhibited considerable potential. However, due to the unsatisfactory cycling and rate performance, their practical application often encounters obstacles. This work reports Fe-based coordination polymers with improved lithium storage performance induced by cobalt ions for the first time. The introduction of cobalt ions is confirmed to obviously increase the active sites and conductivity for the electrode. When used as anode of LIBs, the unique Fe–Co-BDC pencil-like polyhedron exhibits a large reversible capacity of 1188 mAh g−1 at 100 mA g−1 after 300 cycles and also shows a good cycling life at the large currents. The lithium storage mechanism of Fe–Co-BDC is demonstrated to be associated with carboxylate groups and benzene rings of the organic ligands during lithiation and delithiation based on the ex situ FTIR and XPS spectra.

Solid-state reaction synthesis and characterization of Mn-doped LiFePO4 cathode material

Olivine type LiFePO4 has great advantages for Li-ion batteries due to its non-toxicity, high safety, and good cycle life performance. However, its low-rate capability and low energy density make some challenges for this LiFePO4. Several methods like doping with transition metals were used, and Mn ion was used in this work to improve the overall electrochemical properties. LiMn x Fe1-x PO4 is promising cathode material owing to high voltage, structural and chemical stability. However, the electrochemical performance of these materials depends on phases and structures obtained from synthesis. In this work, the effect of solid-state reaction conditions, including calcination temperature and duration, on morphology, structure, and electrochemical properties of LiMn x Fe1-x PO4 cathode materials with the composition of x = 0.5 was investigated. The morphology, crystallography and local structure of the synthesized materials were examined by field emission scanning electron microscope (FE-SEM), X-ray diffractometer (XRD) and Fourier-transform infrared spectrometer (FTIR), respectively. The surface area was also determined by the Brunauer-Emmett-Teller (BET) model. The effect of calcination temperature and reaction time upon the morphology, structures of the synthesized cathode materials were studied and discussed. The results could be essential for further development and employment of LiMn x Fe1-x PO4 in Li-ion batteries.

Electrospun Ti3C2T x MXene and silicon embedded in carbon nanofibers for lithium-ion batteries

In spite of outstanding theoretical specific capacity (∼3590 mAh g−1), huge volume change during lithiation/delithiation and poor conductivity hinder the practical applications of pure Si anodes for lithium ion batteries (LIBs), requiring conductive additives and porous architectures. In this work, flexible and freestanding composite films made of two-dimensional Ti3C2T x MXene nanosheets and silicon particles embedded in carbon nanofiber (denoted as Ti3C2T x -Si@CNF) were prepared via electrospinning and used as LIB anodes. This new electrode design provides a 3D network architecture and high conductivity favorable for good electrochemical performance and long cycle life. Ti3C2T x -Si@CNF electrodes, containing 28% silicon retained high specific capacity of ∼1580 mAh g−1 after 100 cycles at 0.1 A g−1 and 720 mAh g−1 after 1000 cycles at 1 A g−1, and delivered a great rate performance with 289 mAh g−1 at a current density of 5 A g−1. This is a significantly enhanced performance compared with Si particles embedded in CNF without Ti3C2T x (denoted Si@CNF). This work proposes a scalable manufacturing strategy for developing high-performance silicon-based anodes, overcoming the low conductivity and volume expansion issues.

Enabling Reversible MnO2/Mn2+ Transformation by Al3+ Addition for Aqueous Zn-MnO2 Hybrid Batteries.

Aqueous rechargeable Zn-manganese dioxide (Zn-MnO2) hybrid batteries based on dissolution-deposition mechanisms exhibit ultrahigh capacities and energy densities due to the two-electron transformation between MnO2/Mn2+. However, the reported Zn-MnO2 hybrid batteries usually use strongly acidic and/or alkaline electrolytes, which may lead to environmental hazards and corrosion issues of the Zn anodes. Herein, we propose a new Zn-MnO2 hybrid battery by adding Al3+ into the sulfate-based electrolyte. The hybrid battery undergoes reversible MnO2/Mn2+ transformation and exhibits good electrochemical performances, such as a high discharge capacity of 564.7 mAh g-1 with a discharge plateau of 1.65 V, an energy density of 520.8 Wh kg-1, and good cycle life without capacity decay upon 2000 cycles. Experimental results and theoretical calculation suggest that the aquo Al3+ with Brønsted weak acid nature can act as the proton-donor reservoir to maintain the electrolyte acidity near the electrode surface and prevent the formation of Zn4(OH)6(SO4)·0.5H2O during discharging. In addition, Al3+ doping during charging introduces oxygen vacancies in the oxide structure and weakens the Mn-O bond, which facilitates the dissolution reaction during discharge. The mechanistic investigation discloses the important role of Al3+ in the electrolyte, providing a new fundamental understanding of the promising aqueous Zn-MnO2 batteries.

Fabrication of Si@mesocarbon microbead (MCMB) anode based on carbon texture for lithium-ion batteries

Efficient management of the carbon structure is challenging for silicon/carbon anodes for lithium-ion batteries. Here, a uniquely structured composite (Si@MCMB), with silicon nanoparticles (Si NPs) embedded in the turbostratic carbon layer texture of mesocarbon microbeads (MCMB), has been designed. Mesophase pitch was used as the carbon precursor because of its unique carbon layer structure and porosity after carbonization. As a result, the Si@MCMB composite anode showed good cycle life and rate capability compared to materials obtained by the conventional carbon coating method. This arrangement of the turbostratic carbon layer texture should provide silicon volume expansion space, ion/electron diffusion channels, and mechanical strength.

Construction of metal-organic framework derived Co-Mo-S nanosheets arrays as high-performance electrode for battery-supercapacitor hybrid devices

Bimetallic metal-organic framework (MOF) has attracted great interest as an electrode for supercapacitors. Most metal sources are limited to valences of + 2 and + 3. We select metal sources of Co (II) and Mo (VI) and demonstrated a crystalline bimetallic MOF precursor prepared by using a facile chemical synthesis. The one-step solvothermal strategy is assisted by thioacetamide (TAA) for the self-assembly Co-Mo-S nanosheet arrays (Co-Mo-S NSAs). TAA-induced etching is essential to regulate the assembly of amorphous structures. Otherwise, only a single-structure crystalline Co-Mo-S could be obtained. The Co-Mo-S NSAs show a large specific capacitance of 1805.28 F g−1 at a current density of 0.5 A g−1. A Co-Mo-S NSAs//AC battery−supercapacitor hybrid (BSH) make with activated carbon as the negative electrode and Co-Mo-S NSAs as the positive electrode. At a current density of 0.5 A g−1, the BSH shows a high energy density of 169.73 Wh kg−1 and a power density of 371.44 W kg−1. After 50,000 cycles, the capacitance retention rate is as high as 94.44%, showing good reversibility and cycle life. This work provides an effective strategy for manufacturing bimetallic MOF-based metal sulfide heterostructure electrode materials for practical energy storage and conversion.

Microstructure Characterization and Battery Performance Comparison of MOF-235 and TiO2-P25 Materials

The growing interest in energy storage has led to the urgent need for the development of high-performance cathode electrodes. The commercialized materials MOF-235 and TiO2-P25 exhibit characteristics that may be suitable as electrodes but there are inherent challenges that have yet to be addressed in the literature. In this study, a high-pressure hydrothermal synthesized MOF-235 and sol-gel-made TiO2-P25 were tested for battery performance. The results indicate that MOF-235 does not possess the desired performance due to uncontrollable agglomeration. On the other hand, TiO2-P25 showed good cycling life, and the performance can be further optimized by doping and minimizing the particle size. Additionally, SEM and TEM were applied for surface characterization, providing evidence that mesoporous TiO2-25 inhibits photo-generated carrier recombination. The mesoporous energy storage mechanism of those two materials is also discussed. This research will provide technical support for the industrialization of those two mesoporous materials.

Non-aqueous synthesis of high-quality Prussian blue analogues for Na-ion batteries.

A microwave-assisted solvothermal (MW-ST) method was developed to synthesize high-quality Prussian blue analogues. The tuned NaFeHCF exhibits low water content as well as good thermal stability. It delivers a high initial discharge capacity of 150 mA h g-1, good rate capability and cycling life over 500 cycles.

Enhancing the ion accessibility of Ti3C2Tx MXene films by femtosecond laser ablation towards high-rate supercapacitors

MXenes have attracted tremendous attention in the area of electrochemical energy-storage devices owing to their high electrical conductivity, pseudocapacitance and two-dimensional lamellar structure. Nevertheless, MXene flakes intrinsically tend to lie flat and restack, resulting in highly tortuous ion transport pathways and inferior ion accessibility. Herein, we develop a femtosecond laser ablation strategy to fabricate flexible and high-performance MXene ribbon supercapacitor electrodes. The fabricated MXene ribbons have porous edges with exposed continuous lamellar channels, which shortens the H+ transport pathways, impregnates with sufficient electrolyte, benefits for H+ intercalation and ion storage. The resultant MXene ribbons exhibit high specific capacitance (1308.3 mF/cm2), good rate capability and long cycling life (95% capacitance retention and 92% coulombic efficiency after 30,000 cycles). This work provides a new strategy for the rational structure design of high-rate MXene-based supercapacitor electrodes and lays the foundation for the next generation high-performance energy storage devices.

Construction of MoSe2 nanoparticles anchored on layered microporous carbon heterostructure anode for high-performance and low-cost lithium-ion capacitors

Lithium ion capacitors (LICs), which elaborately integrate the feature of supercapacitors and lithium-ion batteries have recently aroused extensive research attentions. Nevertheless, balancing the discrepancy of electrochemical kinetics between capacitive-type cathode and battery-type anode materials plays the pivotal role in constructing high-performance of LICs. Additionally, the cathode and anode of LICs usually adopt various material synthesis routes, making the fabrication procedures complicated and expensive from the perspective of energy storage devices. Herein, the one‑carbon dual-purpose strategy is proposed for simultaneous manipulation of MoSe2/layered microporous carbon heterostructure anode (MoSe2@LMC-1.5) and amorphous microporous carbon cathode (LMC) by using maize stalks precursor. The MoC bond formed on the interface of MoSe2 and LMC favors electron and Li-ion transfer in the composite. The amorphous microporous carbon substrate can not only ameliorate electrical conductivity of molybdenum selenide, but also tremendously suppress serious agglomeration of MoSe2 nanoparticles. The optimized mass ratio MoSe2@LMC-1.5 heterostructure remarkably improves the lithium ion storage performance. More importantly, in the potential window (0–4.5 V), LIC (MoSe2@LMC-1.5//LMC) device displays a higher energy/power output (maximum 108 Wh kg−1/221 W kg−1 and 68 Wh kg−1/2295 W kg−1) along with good cycling life.

Carbon Materials for Development of High Power and High Energy Density Lithium Ion Capacitors

Lithium ion capacitor is a hybrid technology that integrates high surface area carbon cathode and prelithiated lithium anode materials to deliver a high energy density, high power density energy storage solution with good cycle life. In this investigation, we report the synthesis of a bimodal porous carbon electrode derived from polymer precursor for use as cathode with optimum hierarchical porosity that can deliver high specific capacitance and good high voltage electrochemical stability. Additionally, we also demonstrate the possibility of prelithiation of various graphitic materials for use as anode. Specifically, we fabricate a coalesced carbon onion based anode with rate capability as high as 100C. The assembled lithium ion capacitor shows over 80% capacitance retention over 21000 cycles. We also show that it is possible to package these materials in a 2016 coincell prototype and deliver an energy density of 13 Wh/L volumetrically based on packaged device. The device has been shown to be useful in developing self-powered health sensor platforms.

High Energy Density Li-Ion Capacitor for Use in Wearable Health Sensor Platforms

Lithium ion capacitors with their high energy density, high power density and good cycle life can offer potential standalone energy storage solution when combined with renewable energy harvesting technologies to power wearable health sensor or Internet of things platform. In this study, we demonstrate fabrication of 13 Wh/L packaged Li-ion capacitor 2016 coincell prototype that can be charged using harvested solar energy from indoor lighting to power wearable health sensor platforms. The capacitor with its extremely low self-discharge rate, high load carrying capability and cycle life can provide significant advantages relative to rechargeable batteries of similar form factor. The study provides a comparison of performance of Li-ion rechargeable battery against the fabricated capacitor to continuously power wearable heath sensor platform.

Dy doped Gd2Zr2O7 thermal barrier coatings: Thermal expansion coefficient, microstructure and failure mechanism

Thermal barrier coatings (TBCs) are of great interest in increasing the service temperature and improving the efficiency of aircraft engine. In this study, the GdDyZrO and YSZ were deposited by electron beam-physical vapor deposition. The effect of Dy stabilization on phase structure, thermal expansion coefficient and failure behaviors has been characterized and investigated in detail. The TBCs exhibit high thermal expansion coefficient and good thermal cycling life at 1100 °C. The lager amount of cracks are detected in thermally grown oxide layer in the end. The thickness of thermally grown oxide reaches approximately 20 µm. The interface instability in TBCs system might be relevant with failure behaviors of TBCs.

Xylitol-Maleic Anhydride as Small-Molecule Binders for Silicon Anodes in Lithium-Ion Batteries

The theoretical capacity (∼4200 mAh g−1) of silicon (Si) electrode is almost tenfold higher than that of commercially available graphite. However, the cycle-life performance of the Si electrode is poor. Herein, small molecules, sugar alcohol (xylitol) and maleic anhydride, are used as an aqueous binder to obtain high-performance Si electrodes. The xylitol-maleic anhydride (X-MA) binder is in situ polymerized by esterification of maleic anhydride with xylitol and oxa-Michael addition of an α,β-unsaturated ester with hydroxyl groups of xylitol during the preparation of slurry and the drying of electrode. The X-MA binder is characterized by Fourier-transform infrared and solid-state 13C nuclear magnetic resonance spectroscopy, confirming that the esterification and oxa-Michael addition reactions occur during the fabrication of Si electrodes. The results of thermogravimetric analysis and differential scanning calorimetry show that X-MA has good thermal stability and is an elastomer. The 180° peeling test results indicate that the presence of hydroxyl groups in the xylitol moiety results in a strong interaction between the binder and Si nanoparticles, improving the mechanical properties of the Si electrode. Furthermore, the Si electrode with the X-MA binder exhibits a high energy capacity of 4012 mAh g−1 at 0.1 C, enhanced C-rate performance, and good cycle-life performance.

Ruthenium doped Ge2Sb2Te5 nanomaterial as fast speed phase-change materials with good thermal stability

Ge2Sb2Te5 (GST) as phase-change material has the advantage of good thermal stability and long cycle life, however large power consumption and lower phase change speed partly limit large-scale application for phase-change materials (PCM). In this paper, a comprehensive research is investigated on Ru doped GST phase-change material, from properties to performances for PCM application. Ru doping can efficiently improve the thermal stability of GST alloy and the thickness change of Ru0.05(GST)0.95 film is 3.3%. In addition, high 10-year data retention temperature (∼151 °C) and small crystal grain reflect the advantages of data retention and low power consumption for Ru0.05(GST)0.95 film. Furthermore, the structure characteristics show the stable face-centred cubic structure at crystalline state after annealing. As for electrical properties, Ru0.05(GST)0.95-based PCM cell shows excellent reversible SET-RESET properties with a suitable operation window and good endurance up to 106 electrical cycles with a resistance ratio of about 10. And also, it has a dramatically lower power consumption of 1.46 × 10-11 J compared with GST-based cell (4.76 × 10-10 J), making it a promising material for the Internet of Things (IOT) field applications.

Zinc-based energy storage with functionalized carbon nanotube/polyaniline nanocomposite cathodes

Aqueous zinc-based electrochemical energy storage (EES) systems including zinc-ion batteries and zinc-ion hybrid supercapacitors are increasingly studied, due to their great potential for safe, high-power and wearable energy storage. The electrochemical performance of zinc-based EES systems is strongly affected by cathode materials. Herein, functionalized carbon nanotube (f-CNT)/polyaniline (PANI) nanocomposites were synthesized by in-situ polymerization of PANI on f-CNTs and then used as cathode materials for zinc-based EES systems. Benefiting from better hydrophilicity and chemical adsorption ability of Zn2+, f-CNTs are superior to pristine CNTs in electrochemical performance, and the f-CNT/PANI nanocomposites effectively integrated capacitive energy storage mechanism of f-CNTs with redox reaction energy storage mechanism of PANI, thereby exhibiting superior comprehensive electrochemical properties including high capacity, good rate performance and long cycle life. Moreover, high-performance and flexible zinc-based EES devices were constructed with the f-CNT/PANI nanocomposite cathodes. This work is expected to provide new thoughts to achieve high-performance and flexible zinc-based EES.

Rich Oxygen‐Containing Carbon Microparticles Derived from Self‐Assembled Polyimides for High‐Performance Supercapacitors

Novel porous carbon microparticles derived from self‐assembled polyimides (PIs) were prepared via a facile solvothermal strategy, followed by thermally rearranged treatment and pyrolysis process. Without additional activation, the carbon microparticles exhibited large specific surface areas and abundant oxygen and nitrogen contents. Herein, the PIs microparticles derived from 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride and 3,3′‐diamino‐4,4′‐dihydroxybiphenyl, are self‐assembled by nanoscale layers. Due to thermally rearranged process, the as‐prepared carbon microparticles contain a large number of micropores and mesopores, resulting in large specific surface area of 1070.7 m2 g−1. Due to the rich oxygen of 10.96%, HPI‐90‐2‐900 offers higher specific capacitance of 263.7 F g−1 when the current density is 0.5 A g−1. In addition, the specific capacitances are maintained by 67.5% when the current density is enhanced to 10 A g−1. The long‐term stability test shows that the retention rate of specific capacitance is close to 100% after 10 000 cycles of charge and discharge when the current density was 1 A g−1, indicating a good cycle life. Moreover, a light‐emitting diode is successfully lighted up by the coin cells. Therefore, a facile strategy to improve the electrochemical performance of carbon microparticles to meet the requirements of energy storage and conversion is provided.

Nanostructured MoS2‐, SnS2‐, and WS2‐Based Anode Materials for High‐Performance Sodium‐Ion Batteries via Chemical Methods: A Review Article

In the current age, electric‐driven products based on large‐scale stationary energy‐storage devices, sodium‐ion batteries (SIBs) are good promising candidates due to their comparable low cost, environment friendliness, high efficiency, and relatable huge abundance. An anode plays a vital role in the high performance of rechargeable batteries, so it becomes necessary to focus on the research on high‐performance anode materials. Recently, a number of researchers developed advanced host materials for SIBs to boost their energy density, cycle efficiency, and safety measures. In recent years, nanostructured metal sulfides like MoS2, SnS2, and WS2 with their novel structure‐based anode materials are the focus of the key research in sodium‐storage applications because of their comparable high conductivity, high capacity, good cycle life, and unmatched chemical and physical properties. In addition, these metal sulfides exhibit high mechanical, thermal, and structural stability, which supports them to find their place as an anode material for high‐performance SIBs in large‐scale energy storage production. Herein, the selected metal sulfide‐based nanostructures synthesized by chemical routes are extensively reviewed and their electrochemical properties for application as a high‐performance anode material in the SIBs are explored.

α-MnO2 Nanowires and Amino-Modified Reduced Graphene Oxide Hybrid Films for Constructing the Flexible High-Performance Symmetrical Supercapacitors

Graphene or its derivates are used as an electrode material for the fabrication of supercapacitors (SCs). However, graphene or its composites readily agglomerate or stack in water, which seriously imparts SC energy efficiency. Presently, we used a new composite using [Formula: see text]-MnO2 nanowires and nitrogen-doped reduced graphene oxide ([Formula: see text]-MnO2/NRGO) for the fabrication of electrodes required in symmetric SCs. Hydrothermally synthesized [Formula: see text]-MnO2 nanowires have a smooth surface, good dispersion, and a high length-to-width ratio. The formation of stable and densely networked structures and the synergy between NRGO and [Formula: see text]-MnO2 nanowires enable the [Formula: see text]-MnO2/NRGO film electrode to show a large area-specific capacitance (386.8[Formula: see text]mF[Formula: see text]cm[Formula: see text]) at 1[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] current density; the capacity retention is 62.4% when the current density increases from 1[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] to 10[Formula: see text]mA[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text]. The flexible and symmetrical [Formula: see text]-MnO2/NRGO SC was assembled using [Formula: see text]-MnO2/NRGO film electrodes in 1 M Na2SO4 electrolyte with a cellulose paper separator, has good capacitance retention (94%), excellent Coulombic efficiency (99%) after 3000 cycles, and high energy density (28.22[Formula: see text][Formula: see text]Wh[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text]) at 0.8[Formula: see text]mW[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] power density. The [Formula: see text]-MnO2 nanowires/NRGO hybrid film flexible and symmetrical SCs are characterized by high energy storage, good cycle life and Columbic efficiency, which offer promising applications in the portable and wearable electronics industry.