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

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.

2018 ◽  
Vol 5 (1) ◽  
pp. 171186 ◽  
Author(s):  
Guofu Ma ◽  
Fengting Hua ◽  
Kanjun Sun ◽  
Enke Fenga ◽  
Hui Peng ◽  
...  

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.


2018 ◽  
Vol 47 (23) ◽  
pp. 7747-7753 ◽  
Author(s):  
Qiufan Wang ◽  
Xiao Liang ◽  
Yun Ma ◽  
Daohong Zhang

A novel type of asymmetric supercapacitor was fabricated by assembling a RuO2 positive electrode and a Fe2O3 negative electrode. Full cells are constructed and show a high capacitance of 4.9 F cm−3, a high energy density of 1.5 mW h cm−3 and a high power density of 9.1 mW cm−3.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Lei Zheng ◽  
Feng Guo ◽  
Tuo Kang ◽  
Yingzhu Fan ◽  
Wei Gu ◽  
...  

AbstractLithium metal is regarded as the ultimate negative electrode material for secondary batteries due to its high energy density. However, it suffers from poor cycling stability because of its high reactivity with liquid electrolytes. Therefore, continuous efforts have been put into improving the cycling Coulombic efficiency (CE) to extend the lifespan of the lithium metal negative electrode. Herein, we report that using dual-salt additives of LiPF6 and LiNO3 in an ether solvent-based electrolyte can significantly improve the cycling stability and rate capability of a Li-carbon (Li-CNT) composite. As a result, an average cycling CE as high as 99.30% was obtained for the Li-CNT at a current density of 2.5 mA cm–2 and an negative electrode to positive electrode capacity (N/P) ratio of 2. The cycling stability and rate capability enhancement of the Li-CNT negative electrode could be attributed to the formation of a better solid electrolyte interphase layer that contains both inorganic components and organic polyether. The former component mainly originates from the decomposition of the LiNO3 additive, while the latter comes from the LiPF6-induced ring-opening polymerization of the ether solvent. This novel surface chemistry significantly improves the CE of Li negative electrode, revealing its importance for the practical application of lithium metal batteries.


2018 ◽  
Vol 6 (4) ◽  
pp. 1802-1808 ◽  
Author(s):  
Ke Li ◽  
Yanshan Huang ◽  
Jingjing Liu ◽  
Mansoor Sarfraz ◽  
Phillips O. Agboola ◽  
...  

Three-dimensional graphene frameworks enable the development of stretchable asymmetric supercapacitors with a record high energy density of 77.8 W h kg−1, and also excellent stretchability and superior cycling stability.


2015 ◽  
Vol 3 (31) ◽  
pp. 16150-16161 ◽  
Author(s):  
Dezhi Kong ◽  
Chuanwei Cheng ◽  
Ye Wang ◽  
Jen It Wong ◽  
Yaping Yang ◽  
...  

A novel asymmetric supercapacitor composed of Co3O4@C@Ni3S2 NNAs as the positive electrode and activated carbon (AC) as the negative electrode can deliver a high energy density and excellent long cycle stability.


NANO ◽  
2020 ◽  
Vol 15 (10) ◽  
pp. 2050136
Author(s):  
Xuan Zheng ◽  
Xingxing He ◽  
Jinlong Jiang ◽  
Zhengfeng Jia ◽  
Yu Li ◽  
...  

In this paper, the Ni[Formula: see text]Co[Formula: see text]S4@CNTs nanocomposites containing different carbon nanotubes (CNT) content were prepared by a one-step hydrothermal method. More hydroxyl and carboxyl groups were introduced on the surface of CNTs by acidizing treatment to increase the dispersion of CNTs. The acid-treated CNTs can more fully compound with Ni[Formula: see text]Co[Formula: see text]S4 nanoparticles to form heterostructure. When the CNTs content is 10[Formula: see text]wt.%, the Ni[Formula: see text]Co[Formula: see text]S4@CNTs-10 nanocomposite exhibits the highest specific capacity of 210[Formula: see text]mAh[Formula: see text]g[Formula: see text] in KOH aqueous electrolytes at current density of 1[Formula: see text]A[Formula: see text]g[Formula: see text]. The superior performances of the Ni[Formula: see text]Co[Formula: see text]S4@CNTs-10 nanocomposite are attributed to the effective synergic effects of the high specific capacity of Ni[Formula: see text]Co[Formula: see text]S4 and the excellent conductivity of CNTs. An asymmetric supercapacitor (ASC) was assembled based on Ni[Formula: see text]Co[Formula: see text]S4@CNTs-10 positive electrode and activated carbon (AC) negative electrode, which delivers a high energy density of 61.2[Formula: see text]Wh[Formula: see text]kg[Formula: see text] at a power density of 800[Formula: see text]W[Formula: see text]kg[Formula: see text], and maintains 34.8[Formula: see text]Wh[Formula: see text]kg[Formula: see text] at a power density of 16079[Formula: see text]W[Formula: see text]kg[Formula: see text]. Also, the ASC device shows an excellent cycling stability with 91.49% capacity retention and above 94% Columbic efficiency after 10 000 cycles at 10[Formula: see text]A[Formula: see text]g[Formula: see text]. This aqueous asymmetric Ni[Formula: see text]Co[Formula: see text]S4@CNTs//AC supercapacitor is promising for practical applications due to its advantages such as high energy density, power delivery and cycling stability.


2014 ◽  
Vol 2 (45) ◽  
pp. 19444-19450 ◽  
Author(s):  
Zheng Chang ◽  
Xujiong Wang ◽  
Yaqiong Yang ◽  
Jie Gao ◽  
Minxia Li ◽  
...  

Li//Br battery, by using aqueous bromide/tribromide redox pair as positive electrode and a coated lithium metal as negative electrode, exhibits high energy density and good cycling.


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1471
Author(s):  
Shan-Ho Tsai ◽  
Ying-Ru Chen ◽  
Yi-Lin Tsou ◽  
Tseng-Lung Chang ◽  
Hong-Zheng Lai ◽  
...  

Lots of lithium ion battery (LIB) products contain lithium metal oxide LiNi5Co2Mn3O2 (LNCM) as the positive electrode’s active material. The stable surface of this oxide results in high resistivity in the battery. For this reason, conductive carbon-based materials, including acetylene black and carbon black, become necessary components in electrodes. Recently, carbon nano-tube (CNT) has appeared as a popular choice for the conductive carbon in LIB. However, a large quantity of the conductive carbon, which cannot provide capacity as the active material, will decrease the energy density of batteries. The ultra-high cost of CNT, compared to conventional carbon black, is also a problem. In this work, we are going to introduce long-length carbon nano-tube s(L-CNT) into electrodes in order to design a reduced-amount conductive carbon electrode. The whole experiment will be done in a 1Ah commercial type pouch LIB. By decreasing conductive carbon as well as increasing the active material in the positive electrode, the energy density of the LNCM-based 1Ah pouch type LIB, with only 0.16% of L-CNT inside the LNCM positive electrode, could reach 224 Wh/kg and 549 Wh/L, in weight and volume energy density, respectively. Further, this high energy density LIB with L-CNT offers stable cyclability, which may constitute valuable progress in portable devices and electric vehicle (EV) applications.


2018 ◽  
Vol 47 (47) ◽  
pp. 17146-17152 ◽  
Author(s):  
Xiao Liang ◽  
Qiufan Wang ◽  
Yun Ma ◽  
Daohong Zhang

A two-ply CNT yarn asymmetric supercapacitor was fabricated by assembling a CuCo2O4 nanowire positive electrode and a PPy nanoparticle negative electrode. The full cell exhibits a high specific capacitance of 59.55 mF cm−2 and a high energy density of 0.02 mW h cm−2.


Sign in / Sign up

Export Citation Format

Share Document