scholarly journals Exploring the Role of Crystal Water in Potassium Manganese Hexacyanoferrate as a Cathode Material for Potassium-Ion Batteries

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 895
Author(s):  
Polina A. Morozova ◽  
Ivan A. Trussov ◽  
Dmitry P. Rupasov ◽  
Victoria A. Nikitina ◽  
Artem M. Abakumov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Electrochemical Performance ◽  
Structural Model ◽  
Electrode Materials ◽  
Iron Oxidation ◽  
Specific Capacity ◽  
Potassium Ion ◽  
Potential Range ◽  
Crystal Water

The Prussian Blue analogue K2−δMn[Fe(CN)6]1−ɣ∙nH2O is regarded as a key candidate for potassium-ion battery positive electrode materials due to its high specific capacity and redox potential, easy scalability, and low cost. However, various intrinsic defects, such as water in the crystal lattice, can drastically affect electrochemical performance. In this work, we varied the water content in K2−δMn[Fe(CN)6]1−ɣ∙nH2O by using a vacuum/air drying procedure and investigated its effect on the crystal structure, chemical composition and electrochemical properties. The crystal structure of K2−δMn[Fe(CN)6]1−ɣ∙nH2O was, for the first time, Rietveld-refined, based on neutron powder diffraction data at 10 and 300 K, suggesting a new structural model with the Pc space group in accordance with Mössbauer spectroscopy. The chemical composition was characterized by thermogravimetric analysis combined with mass spectroscopy, scanning transmission electron microscopy microanalysis and infrared spectroscopy. Nanosized cathode materials delivered electrochemical specific capacities of 130–134 mAh g−1 at 30 mA g−1 (C/5) in the 2.5–4.5 V (vs. K+/K) potential range. Diffusion coefficients determined by potentiostatic intermittent titration in a three-electrode cell reached 10−13 cm2 s−1 after full potassium extraction. It was shown that drying triggers no significant changes in crystal structure, iron oxidation state or electrochemical performance, though the water level clearly decreased from the pristine to air- and vacuum-dried samples.

scholarly journals Ce-Doped PANI/Fe3O4 Nanocomposites: Electrode Materials for Supercapattery

2021 ◽  
Vol 3 ◽  
Author(s):  
Subash Pandey ◽  
Shova Neupane ◽  
Dipak Kumar Gupta ◽  
Anju Kumari Das ◽  
Nabin Karki ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrode Material ◽  
High Performance ◽  
Electrode Materials ◽  
Specific Capacity ◽  
Maximum Energy ◽  
Potential Range ◽  
X Ray Diffraction ◽  
Active Electrode ◽  
Transmission Electron

In this study, we report on a combined approach to preparing an active electrode material for supercapattery application by making nanocomposites of Polyaniline/Cerium (PANI/Ce) with different weight percentages of magnetite (Fe3O4). Fourier-transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) analyses supported the interaction of PANI with Ce and the formation of the successful nanocomposite with magnetite nanoparticles. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses showed the uniform and porous morphology of the composites. Cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) were used to test the supercapattery behavior of the nanocomposite electrodes in 1.0 M H2SO4. It was found that the supercapattery electrode of PANI/Ce+7 wt.% Fe3O4 exhibited a specific capacity of 171 mAhg−1 in the potential range of −0.2 to 1.0 V at the current density of 2.5 Ag−1. Moreover, PANI/Ce+7 wt.% Fe3O4 revealed a power density of 376.6 Wkg−1 along with a maximum energy density of 25.4 Whkg−1 at 2.5 Ag−1. Further, the cyclic stability of PANI/Ce+7 wt.% Fe3O4 was found to be 96.0% after 5,000 cycles. The obtained results suggested that the PANI/Ce+Fe3O4 nanocomposite could be a promising electrode material candidate for high-performance supercapattery applications.

scholarly journals Nanohollow Carbon for Rechargeable Batteries: Ongoing Progresses and Challenges

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiangmin Jiang ◽  
Guangdi Nie ◽  
Ping Nie ◽  
Zhiwei Li ◽  
Zhenghui Pan ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Carbon Nanostructures ◽  
Active Sites ◽  
Electrode Materials ◽  
Mechanical Stability ◽  
High Surface ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Rechargeable Batteries

AbstractAmong the various morphologies of carbon-based materials, hollow carbon nanostructures are of particular interest for energy storage. They have been widely investigated as electrode materials in different types of rechargeable batteries, owing to their high surface areas in association with the high surface-to-volume ratios, controllable pores and pore size distribution, high electrical conductivity, and excellent chemical and mechanical stability, which are beneficial for providing active sites, accelerating electrons/ions transfer, interacting with electrolytes, and giving rise to high specific capacity, rate capability, cycling ability, and overall electrochemical performance. In this overview, we look into the ongoing progresses that are being made with the nanohollow carbon materials, including nanospheres, nanopolyhedrons, and nanofibers, in relation to their applications in the main types of rechargeable batteries. The design and synthesis strategies for them and their electrochemical performance in rechargeable batteries, including lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, and lithium–sulfur batteries are comprehensively reviewed and discussed, together with the challenges being faced and perspectives for them.

scholarly journals Understanding sodium-ion diffusion in layered P2 and P3 oxides via experiments and first-principles calculations: a bridge between crystal structure and electrochemical performance

2016 ◽  
Vol 8 (4) ◽  
pp. e266-e266 ◽  
Author(s):  
Shaohua Guo ◽  
Yang Sun ◽  
Jin Yi ◽  
Kai Zhu ◽  
Pan Liu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electrochemical Performance ◽  
Density Functional ◽  
Electrode Materials ◽  
Rate Capability ◽  
Sodium Ion ◽  
Atomic Scale ◽  
Sodium Ion Batteries ◽  
P Type ◽  
The Relationship

Abstract Layered Na x MeO2 (Me=transition metal) oxides, the most common electrode materials for sodium-ion batteries, fall into different phases according to their stacking sequences. Although the crystalline phase is well known to largely influence the electrochemical performance of these materials, the structure–property relationship is still not fully experimentally and theoretically understood. Herein, a couple consisting of P2-Na0.62Ti0.37Cr0.63O2 and P3-Na0.63Ti0.37Cr0.63O2 materials having nearly the same compositions is reported. The atomic crystal structures and charge compensation mechanism are confirmed by atomic-scale characterizations in the layered P2 and P3 structures, respectively, and notably, the relationship of the crystal structure–electrochemical performance is well defined in the layered P-type structures for the first time in this paper. The electrochemical results suggest that the P2 phase exhibits a better rate capability and cycling stability than the P3 phase. Density functional theory calculations combined with a galvanostatic intermittent titration technique indicates that the P2 phase shows a lower Na diffusion barrier in the presence of multi-Na vacancies, accounting for the better rate capability of the P2 phase. Our results reveal the relationship between the crystal structure and the electrochemical properties in P-type layered sodium oxides, demonstrating the potential for future electrode advancements for applications in sodium-ion batteries.

Microstructure and electrochemical performance of LiFePO4 cathode materials modified with binuclear metal aminophthalocyanines

2018 ◽  
Vol 22 (12) ◽  
pp. 1072-1081 ◽  
Author(s):  
Yuanyuan Su ◽  
Feifei Xu ◽  
Ruiqiong Wang ◽  
Ronglan Zhang ◽  
Jianshe Zhao
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Electrode Materials ◽  
Preparation Method ◽  
Solvothermal Method ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Initial Discharge ◽  
Lifepo4 Cathode ◽  
Binuclear Metal

The monodispersed LiFe[Formula: see text]M[Formula: see text]PO4/C [[Formula: see text] [Formula: see text] 0.0040; [Formula: see text] = Mn[Formula: see text], Co[Formula: see text], Ni[Formula: see text], Cu[Formula: see text], Zn[Formula: see text]] nanocomposites obtained by LiFePO4 modified with binuclear metal aminophthalocyanines (M2(PcTa)2O and M2(PcTa)2C(CF[Formula: see text] are utilized as positive electrode materials for lithium ion batteries. The preparation method for these nanocomposites is a controllable solvothermal method using a mixture of ethylene glycol and [Formula: see text],[Formula: see text]-dimethylformamide as the solvent. The microstructure and electrochemical properties of the different nanocomposites are discussed and compared. The results show that the LiFePO4 samples modified with M2(PcTa)2C(CF[Formula: see text]can improve the initial discharge specific capacity of the lithium ion battery up to 154.2 mAh.g[Formula: see text]at the rate of 0.1 C, and 93.5% of the initial discharge capacity could be retained after 50 cycles. This research shows that the proposed process can enhance the electrochemical performance of high power LiFePO4 for lithium ion batteries.

A novel ferrocene-containing aniline copolymer: its synthesis and electrochemical performance

RSC Advances ◽  
2015 ◽  
Vol 5 (18) ◽  
pp. 14053-14060 ◽  
Author(s):  
Chang Su ◽  
Lvlv Ji ◽  
Lihuan Xu ◽  
Xiaogang Zhu ◽  
Huihui He ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Specific Capacity ◽  
Potential Range ◽  
The Novel ◽  
Discharge Specific Capacity ◽  
Initial Discharge

The novel ferrocene-contained aniline based polymers were successfully synthesized, which demonstrated an improved discharge plateau at the potential range of about 3.0–4.0 V, as with the acceptable initial discharge specific capacity.

scholarly journals Ultrathin Ni1− x Co x S2 nanoflakes as high energy density electrode materials for asymmetric supercapacitors

2019 ◽  
Vol 10 ◽  
pp. 2207-2216 ◽  
Author(s):  
Xiaoxiang Wang ◽  
Teng Wang ◽  
Rusen Zhou ◽  
Lijuan Fan ◽  
Shengli Zhang ◽  
...  
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Power Density ◽  
Active Sites ◽  
Electrode Materials ◽  
Specific Capacity ◽  
High Energy ◽  
High Energy Density ◽  
Oxide Material ◽  
Energy Storage Devices

Transition metal compounds such as nickel cobalt sulfides (Ni–Co–S) are promising electrode materials for energy storage devices such as supercapacitors owing to their high electrochemical performance and good electrical conductivity. Developing ultrathin nanostructured materials is critical to achieving high electrochemical performance, because they possess rich active sites for electrochemical reactions, shortening the transport path of ions in the electrolyte during the charge/discharge processes. This paper describes the synthesis of ultrathin (around 10 nm) flower-like Ni1− x Co x S2 nanoflakes by using templated NiCo oxides. The as-prepared Ni1− x Co x S2 material retained the morphology of the initial NiCo oxide material and exhibited a much improved electrochemical performance. The Ni1− x Co x S2 electrode material exhibited a maximum specific capacity of 1066.8 F·g−1 (533.4 C·g−1) at 0.5 A·g−1 and a capacity retention of 63.4% at 20 A·g−1 in an asymmetric supercapacitor (ASC). The ASC showed a superior energy density of 100.5 Wh·kg−1 (at a power density of 1.5 kW·kg−1), an ultrahigh power density of 30 kW·kg−1 (at an energy density of 67.5 Wh·kg−1) and excellent cycling stability. This approach can be a low-cost way to mass-produce high-performance electrode materials for supercapacitors.

Flexible α-Fe2O3 nanorod electrode materials for sodium-ion batteries with excellent cycle performance

2018 ◽  
Vol 11 (06) ◽  
pp. 1840002 ◽  
Author(s):  
Depeng Zhao ◽  
Di Xie ◽  
Hengqi Liu ◽  
Fang Hu ◽  
Xiang Wu
Keyword(s):  
Electrochemical Performance ◽  
Flexible Electronics ◽  
Electrode Materials ◽  
Specific Capacity ◽  
Rechargeable Batteries ◽  
Sodium Ion ◽  
Cycle Performance ◽  
Carbon Cloth ◽  
Sodium Ion Batteries ◽  
Performance Measurements

With the rise of flexible electronics, flexible rechargeable batteries have attracted widespread attention as a promising power source in new generation flexible electronic devices. In this work, [Formula: see text]-Fe2O3 nanorods grown on carbon cloth have been synthesized through a facile hydrothermal method as binder-free electrode material. The electrochemical performance measurements show that [Formula: see text]-Fe2O3 nanorods possess high specific capacitance and specific capacity retention of 119% after 100 cycles. The combination of low-cost and excellent electrochemical performance makes [Formula: see text]-Fe2O3 nanorods promising anode materials for sodium-ion batteries.

scholarly journals P2- a2=3Mn2=3M1=3O2 (M = Fe, Co, Ni) cathode materials in localized high concentration electrolyte for the long-cycling performance of sodium-ion batteries

2021 ◽  
Vol 24 (2) ◽  
pp. first
Author(s):  
Kha Minh Le ◽  
Huynh Thi Kim Tuyen ◽  
Thanh Duy Vo ◽  
Hoang Van Nguyen ◽  
Nhan Thanh Tran ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Cathode Materials ◽  
Electrode Materials ◽  
Rietveld Method ◽  
Synergistic Effects ◽  
Cycling Performance ◽  
Molar Ratio ◽  
Potential Range ◽  
High Concentration ◽  
Dendrite Formation

Introduction: Localized high concentration electrolytes (LHCE) have been intensively studied due to their unique properties, especially in suppressing the Na dendrite formation and long-term cycling. Therefore, the low electrochemical performance of the P2-type cathode can be overcome by using LHCE. Methods: P2-type sodium layered oxides Na2=3Mn2=3M1=3O2 (M = Fe, Co, Ni) cathode materials were synthesized via a simple co-precipitation following a supported solid-state reaction. XRD and Rietveld method analyzed the phase composition and lattice parameters. SEM images observed the morphology of materials. The half-cell of three cathode were performed in LHCE consisting of 2.1 M sodium bis(fluorosulfonyl)imide (NaFSI) dissolved in 1,2-dimethoxyethane (DME) and bis(2,2,2-trifluoroethyl) ether (BTFE) (solvent molar ratio 1:2). The galvanostatic charge-discharge, striping-plating, and linear sweep voltage tests were carried out to investigate the electrochemical behaviors. Results: As-prepared electrode materials exhibited discharge capacities of 94.5, 147.1, and 142.9 mAh/g at C/10 in the potential range of 1.5-4.2 V for Na2=3Mn2=3Fe1=3O2 (MFO), Na2=3Mn2=3Co1=3O2 (MCO) and Na2=3Mn2=3Ni1=3O2 (MNO), respectively. Interestingly, the MNO cathode material has a superior cycling performance with 86.5% capacity retention after 100 cycles than MCO and MFO. Conclusion: Such superior electrochemical performance of synthesized MNO could be ascribed to the combined synergistic effects between the nickel partially substituted MNO cathode structure and using LHCE 2.1 M NaFSI/DME-BTFE (1:2). Nickel substituted MNO cathode exhibited the enhancement of discharge capacity and the long cycling stability in LHCE due to the mitigation of dendrite formation on sodium metal anode.

scholarly journals Effects of F-Doping on the Electrochemical Performance of Na2Ti3O7 as an Anode for Sodium-Ion Batteries

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2206 ◽  
Author(s):  
Zehua Chen ◽  
Liang Lu ◽  
Yu Gao ◽  
Qixiang Zhang ◽  
Chuanxiang Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electrochemical Performance ◽  
Specific Capacity ◽  
Rate Capability ◽  
Cycling Performance ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Ion Diffusion ◽  
X Ray Diffraction ◽  
Phase Crystal

The effects of fluorine (F) doping on the phase, crystal structure, and electrochemical performance of Na2Ti3O7 are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical measurements. F-doping does not change the crystal structure of NTO, although it has an effect on the morphology of the resultant product. As an anode material for sodium-ion batteries, the specific capacity of Na2Ti3O7 exhibits a 30% increase with F-doping owing to the improved sodium ion diffusion coefficient. F-doped Na2Ti3O7 also displays an enhanced rate capability and favourable cycling performance for more than 800 cycles.

Enhanced Electrochemical Performance of MOF-Derived Nitrogen-Enriched Porous Carbon Coated with Ag as the Cathode for Lithium-Sulfur Batteries

NANO ◽  
2021 ◽  
Author(s):  
Wei Zhao ◽  
Wangjun Feng ◽  
Zhaojiao Shi ◽  
Jingzhou Chen
Keyword(s):  
Electrochemical Performance ◽  
Porous Carbon ◽  
Electrode Materials ◽  
Specific Capacity ◽  
High Energy ◽  
High Energy Density ◽  
Rapid Decline ◽  
Battery Capacity ◽  
Lithium Sulfur Batteries ◽  
Lithium Sulfur

To fulfill the increasing energy demand, lithium-sulfur batteries (LIBs) are considered one of the most promising energy storage devices for the next generation because of their high specific capacity (1675[Formula: see text]mAh[Formula: see text]g[Formula: see text] and high energy density (2600[Formula: see text]Wh[Formula: see text]kg[Formula: see text]. However, the low conductivity of electrode materials, large volume expansion rate and shuttle effect, rapid decline of battery capacity and low cycle lifetime have restricted the commercialization of LIBs. In this paper, a type of silver-coated Co@NC porous carbon (ZIF-67 derivatives) is used as the principal material of the lithium-sulfur battery cathode (denoted Ag–Co@NC). These composites not only confine the active materials to the ordered pore structure composites but also inhibit the free migration of polysulfide and improve the redox reaction. Furthermore, uniformly modified silver nanoparticles are beneficial for enhancing the conductivity of Li2S, thus exhibiting good rate performance and capacity and effectively improving the electrochemical performance of the material.

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