scholarly journals New Limits for Stability of Supercapacitor Electrode Material Based on Graphene Derivative

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1731
Author(s):  
Veronika Šedajová ◽  
Petr Jakubec ◽  
Aristides Bakandritsos ◽  
Václav Ranc ◽  
Michal Otyepka
Keyword(s):  
Large Scale ◽  
Electrode Materials ◽  
High Current Density ◽  
Rate Capability ◽  
Cycling Stability ◽  
Supercapacitor Electrode ◽  
Promising Alternative ◽  
Practical Applications ◽  
High Durability ◽  
Graphene Derivatives

Supercapacitors offer a promising alternative to batteries, especially due to their excellent power density and fast charging rate capability. However, the cycling stability and material synthesis reproducibility need to be significantly improved to enhance the reliability and durability of supercapacitors in practical applications. Graphene acid (GA) is a conductive graphene derivative dispersible in water that can be prepared on a large scale from fluorographene. Here, we report a synthesis protocol with high reproducibility for preparing GA. The charging/discharging rate stability and cycling stability of GA were tested in a two-electrode cell with a sulfuric acid electrolyte. The rate stability test revealed that GA could be repeatedly measured at current densities ranging from 1 to 20 A g−1 without any capacitance loss. The cycling stability experiment showed that even after 60,000 cycles, the material kept 95.3% of its specific capacitance at a high current density of 3 A g−1. The findings suggested that covalent graphene derivatives are lightweight electrode materials suitable for developing supercapacitors with extremely high durability.

scholarly journals Electroactive Ultra-Thin rGO-Enriched FeMoO4 Nanotubes and MnO2 Nanorods as Electrodes for High-Performance All-Solid-State Asymmetric Supercapacitors

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 289 ◽  
Author(s):  
Kugalur Shanmugam Ranjith ◽  
Ganji Seeta Rama Raju ◽  
Nilesh R. Chodankar ◽  
Seyed Majid Ghoreishian ◽  
Cheol Hwan Kwak ◽  
...  
Keyword(s):  
Active Sites ◽  
Electrode Materials ◽  
High Current Density ◽  
Rate Capability ◽  
Negative Electrode ◽  
High Energy ◽  
Cycling Stability ◽  
Operating Voltage ◽  
Carbon Cloth ◽  
Wide Operating

A flexible asymmetric supercapacitor (ASC) with high electrochemical performance was constructed using reduced graphene oxide (rGO)-wrapped redox-active metal oxide-based negative and positive electrodes. Thin layered rGO functionality on the positive and the negative electrode surfaces has promoted the feasible surface-active sites and enhances the electrochemical response with a wide operating voltage window. Herein we report the controlled growth of rGO-wrapped tubular FeMoO4 nanofibers (NFs) via electrospinning followed by surface functionalization as a negative electrode. The tubular structure offers the ultrathin-layer decoration of rGO inside and outside of the tubular walls with uniform wrapping. The rGO-wrapped tubular FeMoO4 NF electrode exhibited a high specific capacitance of 135.2 F g−1 in Na2SO4 neutral electrolyte with an excellent rate capability and cycling stability (96.45% in 5000 cycles) at high current density. Meanwhile, the hydrothermally synthesized binder-free rGO/MnO2 nanorods on carbon cloth (rGO-MnO2@CC) were selected as cathode materials due to their high capacitance and high conductivity. Moreover, the ASC device was fabricated using rGO-wrapped FeMoO4 on carbon cloth (rGO-FeMoO4@CC) as the negative electrode and rGO-MnO2@CC as the positive electrode (rGO-FeMoO4@CC/rGO-MnO2@CC). The rationally designed ASC device delivered an excellent energy density of 38.8 W h kg−1 with a wide operating voltage window of 0.0–1.8 V. The hybrid ASC showed excellent cycling stability of 93.37% capacitance retention for 5000 cycles. Thus, the developed rGO-wrapped FeMoO4 nanotubes and MnO2 nanorods are promising hybrid electrode materials for the development of wide-potential ASCs with high energy and power density.

scholarly journals Achieving of High Density/Utilization of Active Groups via Synergic Integration of C=N and C=O Bonds for Ultra-Stable and High-Rate Lithium-Ion Batteries

Research ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Tao Sun ◽  
Zong-Jun Li ◽  
Xin-Bo Zhang
Keyword(s):  
Electrode Materials ◽  
High Current Density ◽  
Low Cost ◽  
Rate Capability ◽  
Lithium Ion ◽  
High Rate ◽  
Electrochemical Performances ◽  
Environmental Friendliness ◽  
Practical Applications ◽  
Organic Electrode

Organic electrode materials are receiving ever-increasing research interest due to their combined advantages, including resource renewability, low cost, and environmental friendliness. However, their practical applications are still terribly plagued by low conductivity, poor rate capability, solubility in electrolyte, and low density/utilization of active groups. In response, herein, as a proof-of-concept experiment, C=N and C=O bonds are synergically integrated into the backbone of pentacene to finely tune the electronic structures of pentacene. Unexpectedly, the firstly obtained unique 5,7,11,14-tetraaza-6,13-pentacenequinone/reduced graphene oxide (TAPQ/RGO) composite exhibits superior electrochemical performances, including an ultra-stable cycling stability (up to 2400 cycles) and good rate capability (174 mAh g−1 even at a high current density of 3.2 A g−1), which might be attributed to the abundant active groups, π-conjugated molecular structure, leaf-like morphology, and the interaction between TAPQ and graphene.

Building sponge-like robust architectures of CNT–graphene–Si composites with enhanced rate and cycling performance for lithium-ion batteries

2015 ◽  
Vol 3 (7) ◽  
pp. 3962-3967 ◽  
Author(s):  
Xiaolei Wang ◽  
Ge Li ◽  
Fathy M. Hassan ◽  
Matthew Li ◽  
Kun Feng ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Materials ◽  
High Performance ◽  
Rate Capability ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Cycling Stability ◽  
Great Promise ◽  
Practical Applications ◽  
Excellent Cycling Stability

High-performance robust CNT–graphene–Si composites are designed as anode materials with enhanced rate capability and excellent cycling stability for lithium-ion batteries. Such an improvement is mainly attributed to the robust sponge-like architecture, which holds great promise in future practical applications.

scholarly journals Nanostructure selenium compounds as pseudocapacitive electrodes for high-performance asymmetric supercapacitor

2018 ◽  
Vol 5 (1) ◽  
pp. 171186 ◽  
Author(s):  
Guofu Ma ◽  
Fengting Hua ◽  
Kanjun Sun ◽  
Enke Fenga ◽  
Hui Peng ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Rate Capability ◽  
Negative Electrode ◽  
High Specific Capacitance ◽  
High Energy ◽  
Cycling Stability ◽  
High Energy Density ◽  
Storage Device ◽  
Asymmetric Supercapacitor ◽  
Capacitance Performance

The electrochemical performance of an energy conversion and storage device like the supercapacitor mainly depends on the microstructure and morphology of the electrodes. In this paper, to improve the capacitance performance of the supercapacitor, the all-pseudocapacitive electrodes of lamella-like Bi 18 SeO 29 /BiSe as the negative electrode and flower-like Co 0.85 Se nanosheets as the positive electrode are synthesized by using a facile low-temperature one-step hydrothermal method. The microstructures and morphology of the electrode materials are carefully characterized, and the capacitance performances are also tested. The Bi 18 SeO 29 /BiSe and Co 0.85 Se have high specific capacitance (471.3 F g –1 and 255 F g –1 at 0.5 A g –1 ), high conductivity, outstanding cycling stability, as well as good rate capability. The assembled asymmetric supercapacitor completely based on the pseudocapacitive electrodes exhibits outstanding cycling stability (about 93% capacitance retention after 5000 cycles). Moreover, the devices exhibit high energy density of 24.2 Wh kg –1 at a power density of 871.2 W kg –1 in the voltage window of 0–1.6 V with 2 M KOH solution.

scholarly journals Hierarchical Porous Carbon Derived from Sichuan Pepper for High-Performance Symmetric Supercapacitor with Decent Rate Capability and Cycling Stability

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 553 ◽  
Author(s):  
Hengshuo Zhang ◽  
Wei Xiao ◽  
Wenjie Zhou ◽  
Shanyong Chen ◽  
Yanhua Zhang
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
High Performance ◽  
High Current Density ◽  
Rate Capability ◽  
Cycling Stability ◽  
Koh Activation ◽  
High Current ◽  
Symmetric Supercapacitor ◽  
Hierarchical Porous

Hierarchical micro-mesoporous carbon (denoted as HPC-2 in this study) was synthesized by pre-carbonization of biomass Sichuan pepper followed by KOH activation. It possessed well-developed porosity with the specific surface area of 1823.1 m2 g−1 and pore volume of 0.906 cm3 g−1, and exhibited impressive supercapacitive behaviors. For example, the largest specific capacitance of HPC-2 was tested to be ca. 171 F g−1 in a three-electrode setup with outstanding rate capability and stable electrochemical property, whose capacitance retention was near 100% after cycling at rather a high current density of 40 A g−1 for up to 10,000 cycles. Furthermore, a two-electrode symmetric supercapacitor cell of HPC-2//HPC-2 was constructed, which delivered the maximum specific capacitance and energy density of ca. 30 F g−1 and 4.2 Wh kg−1, respectively, had prominent rate performance and cycling stability with negligible capacitance decay after repetitive charge/discharge at a high current density of 10 A g−1 for over 10,000 cycles. Such electrochemical properties of HPC-2 in both three- and two-electrode systems are superior or comparable to those of a great number of porous biomass carbon reported previously, hence making it a promising candidate for the development of high-performance energy storage devices.

scholarly journals Roadmap for advanced aqueous batteries: From design of materials to applications

2020 ◽  
Vol 6 (21) ◽  
pp. eaba4098 ◽  
Author(s):  
Dongliang Chao ◽  
Wanhai Zhou ◽  
Fangxi Xie ◽  
Chao Ye ◽  
Huan Li ◽  
...  
Keyword(s):  
Large Scale ◽  
Cost Effective ◽  
Material Design ◽  
Advanced Materials ◽  
Promising Alternative ◽  
Practical Applications ◽  
Limited Output ◽  
Key Issues ◽  
Fundamental Research ◽  
Aqueous Batteries

Safety concerns about organic media-based batteries are the key public arguments against their widespread usage. Aqueous batteries (ABs), based on water which is environmentally benign, provide a promising alternative for safe, cost-effective, and scalable energy storage, with high power density and tolerance against mishandling. Research interests and achievements in ABs have surged globally in the past 5 years. However, their large-scale application is plagued by the limited output voltage and inadequate energy density. We present the challenges in AB fundamental research, focusing on the design of advanced materials and practical applications of whole devices. Potential interactions of the challenges in different AB systems are established. A critical appraisal of recent advances in ABs is presented for addressing the key issues, with special emphasis on the connection between advanced materials and emerging electrochemistry. Last, we provide a roadmap starting with material design and ending with the commercialization of next-generation reliable ABs.

Selective Conversion of Carbon Dioxide to Formate with High Current Densities

2021 ◽  
pp. 2150001
Author(s):  
Xiulin Yang ◽  
Defei Liu ◽  
Shenghong Zhong ◽  
Xiaofeng Zhou ◽  
Kuo-Wei Huang ◽  
...  
Keyword(s):  
Current Density ◽  
Hollow Fiber ◽  
Active Sites ◽  
Large Scale ◽  
High Current Density ◽  
High Current ◽  
Faradaic Efficiency ◽  
Practical Applications ◽  
Selective Conversion ◽  
Current Densities

Selective conversion of CO2 to formate with high current densities is highly desirable but still challenging. Copper hollow fibers with interconnected pore structures were fabricated via a facile method and used as a stand-alone cathode for highly efficient electrochemical reduction of CO2 to formate. Our studies revealed that delivering the reactant CO2 gas to the inner space of the hollow fiber could build up a higher CO2 partial pressure in the pores and presumably reduce the concentration of H[Formula: see text] from the electrolyte to effectively suppress the major competing reaction, hydrogen evolution reaction (HER), from 46.9% faradaic efficiency (FE) to 15.0%. A high selectivity for CO2 reduction to formate with a maximum FE of 77.1% was achieved with a high current density of 34.7[Formula: see text]mA cm[Formula: see text], which is one of the highest FEs on Cu-based materials. Mechanistic studies suggest that the abundant active sites along with the unique crystal facets induced by the high pressure of CO2 at the pore surface in the “gas in” mode are attributed to the superior electroactivity and selectivity for the CO2 reduction to formate. The Cu hollow fiber electrodes exhibit an outstanding long-term stability at high current density, showing great potential for large-scale practical applications.

scholarly journals Pyrrhotite Fe1−xS microcubes as a new anode material in potassium-ion batteries

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Yang Xu ◽  
Farzaneh Bahmani ◽  
Runzhe Wei
Keyword(s):  
Energy Storage ◽  
Anode Material ◽  
Electrode Materials ◽  
Coulombic Efficiency ◽  
Rate Capability ◽  
Lithium Ion ◽  
Potassium Ion ◽  
Promising Alternative ◽  
Storage Technology ◽  
Energy Storage Technology

Abstract Potassium-ion batteries are an emerging energy storage technology that could be a promising alternative to lithium-ion batteries due to the abundance and low cost of potassium. Research on potassium-ion batteries has received considerable attention in recent years. With the progress that has been made, it is important yet challenging to discover electrode materials for potassium-ion batteries. Here, we report pyrrhotite Fe1−xS microcubes as a new anode material for this exciting energy storage technology. The anode delivers a reversible capacity of 418 mAh g−1 with an initial coulombic efficiency of ~70% at 50 mA g−1 and a great rate capability of 123 mAh g−1 at 6 A g−1 as well as good cyclability. Our analysis shows the structural stability of the anode after cycling and reveals surface-dominated K storage at high rates. These merits contribute to the obtained electrochemical performance. Our work may lead to a new class of anode materials based on sulfide chemistry for potassium storage and shed light on the development of new electrochemically active materials for ion storage in a wider range of energy applications.

Highly rate and cycling stable electrode materials constructed from polyaniline/cellulose nanoporous microspheres

2015 ◽  
Vol 3 (32) ◽  
pp. 16424-16429 ◽  
Author(s):  
Dingfeng Xu ◽  
Xu Xiao ◽  
Jie Cai ◽  
Jun Zhou ◽  
Lina Zhang
Keyword(s):  
Hydrogen Bonding ◽  
Ion Channels ◽  
Phytic Acid ◽  
Electrode Materials ◽  
Rate Capability ◽  
Cycling Stability ◽  
High Rate ◽  
High Rate Capability ◽  
Highly Efficient ◽  
Excellent Cycling Stability

Highly efficient electrode materials were constructed from polyaniline/cellulose microspheres (PANI/PA/CM)viaphytic acid (PA) as “bridge” through hydrogen bonding. The electrodes exhibited excellent cycling stability and high rate capability as a result of the superior affinity of cellulose with the electrolyte and the homogeneous nanoporous architecture, leading to good ion channels.

Organic-based active electrode materials for potassium batteries: status and perspectives

2020 ◽  
Vol 8 (34) ◽  
pp. 17296-17325
Author(s):  
Roman R. Kapaev ◽  
Pavel A. Troshin
Keyword(s):  
Energy Density ◽  
Electrode Materials ◽  
Rate Capability ◽  
Cycling Stability ◽  
Active Materials ◽  
Active Electrode ◽  
Density Rate

Performance of organic-based active materials for K-based batteries is reviewed and compared with the best inorganic analogs. Key strategies for improving energy density, rate capability and cycling stability are discussed.

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