scholarly journals A new insight into the rechargeable mechanism of manganese dioxide based symmetric supercapacitors

RSC Advances ◽  
2017 ◽  
Vol 7 (14) ◽  
pp. 8561-8566 ◽  
Author(s):  
Hongyuan Chen ◽  
Sha Zeng ◽  
Minghai Chen ◽  
Yongyi Zhang ◽  
Qingwen Li
Keyword(s):  
Manganese Dioxide ◽  
Specific Capacitance ◽  
Active Material ◽  
Negative Electrode ◽  
Positive Electrode ◽  
Electrochemically Active ◽  
Insight Into

In symmetric supercapacitors based on MnO2, only MnO2 on the negative electrode serves as the electrochemically active material. MnO2 on the negative electrode dissolves and re-deposites on the positive electrode, thus induces a decrease in specific capacitance.

scholarly journals Reaction mechanisms for electrolytic manganese dioxide in rechargeable aqueous zinc-ion batteries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thuy Nguyen Thanh Tran ◽  
Susi Jin ◽  
Marine Cuisinier ◽  
Brian D. Adams ◽  
Douglas G. Ivey
Keyword(s):  
Electron Microscopy ◽  
Manganese Dioxide ◽  
Critical Concentration ◽  
Electrochemical Techniques ◽  
Active Material ◽  
Zinc Ion ◽  
Positive Electrode ◽  
Zinc Hydroxide ◽  
Electrolytic Manganese Dioxide ◽  
Electrolytic Manganese

AbstractThis study reports the phase transformation behaviour associated with electrolytic manganese dioxide (EMD) utilized as the positive electrode active material for aqueous zinc-ion batteries. Electrochemical techniques, including galvanostatic charge–discharge and rotating ring-disk electrode measurements, and microstructural techniques, using X-ray powder diffraction, scanning electron microscopy, and transmission/scanning transmission electron microscopy, were utilized to characterize the positive electrode at different stages of discharge and charge of zinc-ion cells. The results indicate that, during discharge, a fraction of EMD undergoes a transformation to ZnMn2O4 (spinel-type) and Zn2+ is intercalated into the tunnels of the γ- and ε-MnO2 phases, forming ZnxMnO2 (tunnel-type). When a critical concentration of Mn3+ in the intercalated ZnxMnO2 species is reached, a disproportionation/dissolution reaction is triggered leading to the formation of soluble Mn2+ and hydroxide (OH–) ions; the latter precipitates as zinc hydroxide sulfate (ZHS, Zn4(OH)6(SO4)·5H2O) by combination with the ZnSO4/H2O electrolyte. During charge, Zn2+ is reversibly deintercalated from the intergrown tunneled phases (γ-/ε-ZnxMnO2), Mn2+ is redeposited as layered chalcophanite (ZnMn3O7·3H2O), and ZHS is decomposed by protons (H+) formed during the electrochemical deposition of chalcophanite.

Electric Vehicle Battery Simulation: How Electrode Porosity and Thickness Impact Cost and Performance

2021 ◽  
Author(s):  
Yixin Zhao ◽  
Sara Behdad
Keyword(s):  
National Laboratory ◽  
Active Material ◽  
Argonne National Laboratory ◽  
Negative Electrode ◽  
Lithium Ion ◽  
The United States ◽  
Positive Electrode ◽  
Department Of Energy ◽  
United States Department ◽  
And Performance

Abstract Lithium-ion batteries almost exclusively power today’s electric vehicles (EVs). Cutting battery costs is crucial to the promotion of EVs. This paper aims to develop potential solutions to lower the cost and improve battery performance by investigating its design variables: positive electrode porosity and thickness. The open-access lithium-ion battery design and cost model (BatPac) from the Argonne National Laboratory of the United States Department of Energy, has been used for the analyses. Six pouch battery systems with different positive materials are compared in this study (LMO, LFP, NMC 532/LMO, NMC 622, NMC 811, and NCA). Despite their higher positive active material price, nickel-rich batteries (NMC 622, NMC 811, and NCA) present a cheaper total pack cost per kilowatt-hour than other batteries. The higher thickness and lower porosity can reduce the battery cost, enhance the specific energy, lower the battery mass but increase the performance instability. The reliability of the results in this study is proven by comparing estimated and actual commercial EV battery parameters. In addition to the positive electrode thickness and porosity, six other factors that affect the battery’s cost and performance have been discussed. They include energy storage, negative electrode porosity, separator thickness and porosity, and negative and positive current collector thickness.

Polypyrrole and polypyrrole@MnO2 nanowires grown on graphene foam for asymmetric supercapacitor

2020 ◽  
Vol 10 (8) ◽  
pp. 1308-1316
Author(s):  
Shuang Dong ◽  
Zhengyun Wang ◽  
Junlei Wang ◽  
Yin Yao ◽  
Hongfang Liu
Keyword(s):  
Rational Design ◽  
Active Material ◽  
Negative Electrode ◽  
High Energy ◽  
Cycling Stability ◽  
Positive Electrode ◽  
High Energy Density ◽  
Asymmetric Supercapacitor ◽  
Graphene Foam ◽  
Polypyrrole Nanowires

The asymmetric supercapacitor with negative electrode by graphene foam loaded Polypyrrole nanowires (PPy NWs/rGOF) and positive electrode by PPy@MnO2 core–shell nanowires on graphene foam (PPy@MnO2 NWs/rGOF) was developed. The negative electrode was further converted into the positive electrode by one-step redox reaction at room temperature. Graphene foam (rGOF) with unique flexibility, large surface area and high electric conductivity can favor in situ growth of polypyrrole nanowires (PPy NWs) as well as improve cycling stability of the resultant negative electrode. PPy NWs served as the ideal template for the formation of MnO2 shell gives rise to the as-prepared positive electrode with fast electron transport and enhanced active material utilization. Owing to the rational design, the assembled asymmetric supercapacitor was able to be repeatedly discharged/charged at 1.6 V, displaying high energy density of 1.04 mWh cm–3 with improved cycling stability.

Poly(aniline-co-pyrrole)-coated Ni-doped manganese dioxide as electrode materials for supercapacitors

2020 ◽  
Vol 13 (02) ◽  
pp. 2051007
Author(s):  
Jie Dong ◽  
Qinghao Yang ◽  
Qiuli Zhao ◽  
Zhenzhong Hou ◽  
Yue Zhou ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Manganese Dioxide ◽  
Specific Capacitance ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
Cycle Stability ◽  
Mass Ratio ◽  
Scan Rate ◽  
Poly Aniline ◽  
Inorganic And Organic

Electrode materials with a high specific capacitance, outstanding reversibility and excellent cycle stability are constantly pursued for supercapacitors. In this paper, we present an approach to improve the electrochemical performance by combining the advantages of both inorganic and organic. Ni-MnO2/PANi-co-PPy composites are synthesized, with the copolymer of aniline/pyrrole being coated on the surface of Ni-doped manganese dioxide nanospheres. The inorganic–organic composite enables a substantial increase in its specific capacitance and cycle stability. When the mass ratio of Ni-MnO2 to aniline and pyrrole mixed monomer is 1:5, the composite delivers high specific capacitance of 445.49[Formula: see text]F/g at a scan rate of 2[Formula: see text]mV/s and excellent cycle stability of 61.65% retention after 5000 cycles. The results indicate that the Ni-MnO2/PANi-co-PPy composites are promising electrode materials for future supercapacitors application.

scholarly journals Influence of Multivector Field on Paste Preparation and Formation of Negative Electrodes of Lead Batteries

Batteries ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 24
Author(s):  
Boris Shirov ◽  
Vesselin Naidenov ◽  
Urii Markov
Keyword(s):  
Active Material ◽  
Negative Electrode ◽  
Limiting Factors ◽  
Skeletal Structure ◽  
Experimental Result ◽  
External Application ◽  
Electrochemical Processes ◽  
Depth Of Discharge ◽  
Negative Electrodes ◽  
Positive Effect

During the operation of the negative electrode, some critical processes take place, which are limiting factors for the operation of lead–acid batteries. To improve the efficiency of the negative active material and minimize these processes, external application of multivector field is proposed. Two applications of the multivector field are studied: during negative paste preparation and during formation. It is established that, when applying multivector field during negative paste preparation, the chemical processes proceed more efficiently. The results are better phase composition and crystallinity of the cured paste, thus increasing the capacity of the consequently built lead batteries by 12% on average. The application of a multivector field during the formation of negative active materials in lead batteries has a positive effect on the skeletal structure, the size and shape of the Pb crystals. This ensures longer service life, which is confirmed by the 17.5% Depth of Discharge continuous tests on 12 V/75 Ah batteries. The batteries formed under the influence of external multivector field showed 20% longer cycle life. Based on the experimental result, a most probable mechanism of the influence of the multivector field on the chemical and electrochemical processes in lead batteries during negative paste preparation and formation of negative active masses is proposed.

scholarly journals A Hierarchical Architecture of Functionalized Polyaniline/Manganese Dioxide Composite with Stable-Enhanced Electrochemical Performance

2021 ◽  
Vol 5 (5) ◽  
pp. 129
Author(s):  
Yapeng Wang ◽  
Yanxiang Wang ◽  
Chengjuan Wang ◽  
Yongbo Wang
Keyword(s):  
Electrochemical Performance ◽  
Manganese Dioxide ◽  
Specific Capacitance ◽  
Current Density ◽  
Electrode Materials ◽  
High Efficiency ◽  
Scanning Speed ◽  
Hierarchical Architecture ◽  
Electrochemical Window ◽  
A Current

As one of the most outstanding high-efficiency and environmentally friendly energy storage devices, the supercapacitor has received extensive attention across the world. As a member of transition metal oxides widely used in electrode materials, manganese dioxide (MnO2) has a huge development potential due to its excellent theoretical capacitance value and large electrochemical window. In this paper, MnO2 was prepared at different temperatures by a liquid phase precipitation method, and polyaniline/manganese dioxide (PANI/MnO2) composite materials were further prepared in a MnO2 suspension. MnO2 and PANI/MnO2 synthesized at a temperature of 40 °C exhibit the best electrochemical performance. The specific capacitance of the sample MnO2-40 is 254.9 F/g at a scanning speed of 5 mV/s and the specific capacitance is 241.6 F/g at a current density of 1 A/g. The specific capacitance value of the sample PANI/MnO2-40 is 323.7 F/g at a scanning speed of 5 mV/s, and the specific capacitance is 291.7 F/g at a current density of 1 A/g, and both of them are higher than the specific capacitance value of MnO2. This is because the δ-MnO2 synthesized at 40 °C has a layered structure, which has a large specific surface area and can accommodate enough electrolyte ions to participate the electrochemical reaction, thus providing sufficient specific capacitance.

scholarly journals Nano-channel-based physical and chemical synergic regulation for dendrite-free lithium plating

Nano Research ◽  
2021 ◽  
Author(s):  
Qiang Guo ◽  
Wei Deng ◽  
Shengjie Xia ◽  
Zibo Zhang ◽  
Fei Zhao ◽  
...  
Keyword(s):  
Carbon Materials ◽  
Coating Layer ◽  
Effective Interaction ◽  
Debye Length ◽  
Rate Capability ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Positive Electrode ◽  
Lithium Metal ◽  
Interaction Distance

AbstractUncontrollable dendrite growth resulting from the non-uniform lithium ion (Li+) flux and volume expansion in lithium metal (Li) negative electrode leads to rapid performance degradation and serious safety problems of lithium metal batteries. Although N-containing functional groups in carbon materials are reported to be effective to homogenize the Li+ flux, the effective interaction distance between lithium ions and N-containing groups should be relatively small (down to nanometer scale) according to the Debye length law. Thus, it is necessary to carefully design the microstructure of N-containing carbon materials to make the most of their roles in regulating the Li+ flux. In this work, porous carbon nitride microspheres (PCNMs) with abundant nanopores have been synthesized and utilized to fabricate a uniform lithiophilic coating layer having hybrid pores of both the nano- and micrometer scales on the Cu/Li foil. Physically, the three-dimensional (3D) porous framework is favorable for absorbing volume changes and guiding Li growth. Chemically, this coating layer can render a suitable interaction distance to effectively homogenize the Li+ flux and contribute to establishing a robust and stable solid electrolyte interphase (SEI) layer with Li-F, Li-N, and Li-O-rich contents based on the Debye length law. Such a physical-chemical synergic regulation strategy using PCNMs can lead to dendrite-free Li plating, resulting in a low nucleation overpotential and stable Li plating/stripping cycling performance in both the Li‖Cu and the Li‖Li symmetric cells. Meanwhile, a full cell using the PCNM coated Li foil negative electrode and a LiFePO4 positive electrode has delivered a high capacity retention of ∼ 80% after more than 200 cycles at 1 C and achieved a remarkable rate capability. The pouch cell fabricated by pairing the PCNM coated Li foil negative electrode with a NCM 811 positive electrode has retained ∼ 73% of the initial capacity after 150 cycles at 0.2 C.

Recent progress in rechargeable lithium batteries with organic materials as promising electrodes

2016 ◽  
Vol 4 (19) ◽  
pp. 7091-7106 ◽  
Author(s):  
Jian Xie ◽  
Qichun Zhang
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Batteries ◽  
Recent Progress ◽  
Electrode Materials ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Positive Electrode ◽  
Rechargeable Lithium Batteries ◽  
Organic Electrode ◽  
Negative Electrode Materials

Different organic electrode materials in lithium-ion batteries are divided into three types: positive electrode materials, negative electrode materials, and bi-functional electrode materials, and are further discussed.

Electrochemical Properties of Carbon-Coated NbO2 as a Negative Electrode for Lithium-Ion Batteries

2016 ◽  
Vol 724 ◽  
pp. 87-91 ◽  
Author(s):  
Chang Su Kim ◽  
Yong Hoon Cho ◽  
Kyoung Soo Park ◽  
Soon Ki Jeong ◽  
Yang Soo Kim
Keyword(s):  
Electrochemical Properties ◽  
Lithium Ion Batteries ◽  
Ball Milling ◽  
Carbon Coating ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Transfer Resistance ◽  
Carbon Coated

We investigated the electrochemical properties of carbon-coated niobium dioxide (NbO2) as a negative electrode material for lithium-ion batteries. Carbon-coated NbO2 powders were synthesized by ball-milling using carbon nanotubes as the carbon source. The carbon-coated NbO2 samples were of smaller particle size compared to the pristine NbO2 samples. The carbon layers were coated non-uniformly on the NbO2 surface. The X-ray diffraction patterns confirmed that the inter-layer distances increased after carbon coating by ball-milling. This lead to decreased charge-transfer resistance, confirmed by electrochemical impedance spectroscopy, allowing electrons and lithium-ions to quickly transfer between the active material and electrolyte. Electrochemical performance, including capacity and initial coulombic efficiency, was therefore improved by carbon coating by ball-milling.

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