Segmented bi-material electrodes of activated carbon and LiMn2O4 for electrochemical hybrid storage devices: Effect of mass ratio and C-rate on current sharing

2011 ◽  
Vol 56 (3) ◽  
pp. 1288-1293 ◽  
Author(s):  
D. Cericola ◽  
P. Novák ◽  
A. Wokaun ◽  
R. Kötz
2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.


Author(s):  
Juan Yu ◽  
Xuyang Wang ◽  
Jiaxin Peng ◽  
Xuefeng Jia ◽  
Linbo Li ◽  
...  

Abstract Biomass-activated carbon materials are promising electrode materials for lithium-ion hybrid capacitors (LiCs) because of their natural hierarchical pore structure. The efficient utilization of structural pores in activated carbon is very important for their electrochemical performance. Herein, porous biomass-activated carbon (PAC) with large specific surface area was prepared using a one-step activation method with biomass waste as the carbon source and ZnCl2 as the activator. To further improve its pore structure utilization efficiency, the PAC was doped with nitrogen using urea as the nitrogen source. The experimental results confirmed that PAC-1 with a high nitrogen doping level of 4.66% exhibited the most efficient pore utilization among all the samples investigated in this study. PAC-1 exhibited 92% capacity retention after 8000 cycles, showing good cycling stability. Then, to maximize the utilization of high-efficiency energy storage devices, LiNi0.8Co0.15Al0.05O2 (NCA), a promising cathode material for lithium-ion batteries with high specific capacity, was compounded with PAC-1 in different ratios to obtain NCA@PC composites. The NCA@PC-9 composite exhibited excellent capacitance in LiCs and an energy density of 210.9 Wh kg-1 at a high power density of 13.3 kW kg-1. These results provide guidelines for the design of high-performance and low-cost energy storage devices.


MRS Advances ◽  
2016 ◽  
Vol 1 (19) ◽  
pp. 1377-1382
Author(s):  
Uladzimir Novikau ◽  
Sviatlana Filipovich ◽  
Ihar Razanau

ABSTRACTThe present report is dedicated to a study of possible ways of increasing the energy density of the supercapacitor and thus, bridging the gap between the supercapacitor and the battery. Chemical functionalization of carbon nanomaterials, such as carbon nanotubes, activated carbon cloth, and activated carbon powder used as supercapacitor electrodes as well as novel aqueous electrolytes with the electrochemical window of up to 2 V are described. The hybrid approaches to energy storage mechanism in electrochemical energy storage devices are discussed. The first experimental results on the discussed hybrid energy storage devices are presented.


2020 ◽  
Vol 833 ◽  
pp. 129-133
Author(s):  
Ridwan Tobi Ayinla ◽  
John Ojur Dennis ◽  
Hasnah Bt Moh’d Zaid ◽  
Fahad Usman ◽  
Asfand Yar

The advantages of palm kernel shell (PKS) as a renewable and sustainable material for activated carbon production have been explored for various applications such as water treatment, pollutant, pesticide, and heavy metal adsorption. However, the full promises of this material for energy storage devices have not been duly studied. In this research, PKS is physically activated and the effect of particle size on the physical characteristics of the activated char was investigated. Pellet (3 mm), granules (0.4 mm), and powder (0.0075 mm) are the sizes considered in the experiment. The surface morphology, surface area, porosity and functional group at different sized was analyzed. Finally, a suitable particle size was recommended for the electrode material of supercapacitor based on the physical characteristics of the activated carbon.


2020 ◽  
Vol 143 ◽  
pp. 02008
Author(s):  
Wang Shouzhong ◽  
Zhou Zhen ◽  
Zhang Tong ◽  
Fang Xiaojun ◽  
Miao Chaoyang

A sudden leak of phenylamine is an urgent environmental issue due to its liquidity and volatility. To overcome this difficulty, the decontamination efficiency of spray, foam, and activated carbon to phenylamine was explored using simulated leak box. Furthermore, a new decontamination method of foam coupling with acidic spray was proposed to decontaminate phenylamine. Its decontamination efficiency for phenylamine gas was up to 90% after 3 min adsorption at 3:1 mass ratio and phenylamine liquid was solidified quickly.


2013 ◽  
Vol 448-453 ◽  
pp. 1399-1402 ◽  
Author(s):  
Ling Zhao ◽  
Xiao Gu Cheng ◽  
Ping He Yin ◽  
Gang Lu ◽  
Jun Chang Suo

The aim of this study was to check the effectiveness of microelectrolysis for the pretreatment of a municipal landfill leachate with the objective improving its overall biodegradability, evaluated in terms of BOD5/COD ratio, up to a value compatible with biological treatment. The best microelectrolysis operational conditions for achieving the desired COD values were: pH=2.0; granular activated carbon (GAC) =10 g/L; mass ratio of zero iron (Fe0)/GAC=2:1; reaction time=90 min. The BOD5/COD was significantly improved from 0.12 to 0.31, which allowed an almost 85% removal of COD by a sequential activated sludge process. The results show that the microelectrolysis is a promising technology to improve the biodegradability of mature landfill leachate.


2014 ◽  
Vol 07 (01) ◽  
pp. 1350066 ◽  
Author(s):  
Mei-Gen Deng ◽  
Ren-Qing Wang

Petroleum coke (PC) was expanded by using KMnO 4 as oxidant and HClO 4 as intercalator so as to decrease the amount of KOH needed for the successive activation. Activated carbon (AC) was prepared by activation of the expanded PC (EPC) at KOH /coke mass ratio of 3:1 (denoted as EAC-3). As a comparison, AC was also made by activation of PC at KOH /coke mass ratio of 3:1, 4:1 and 5:1 (denoted as AC-3, AC-4 and AC-5). Influence of expanding modification on the structure and performance of PC and AC was investigated. The results revealed that the expanding treatment increased the interplanar distance of PC microcrystalline from 0.344 to 0.362 nm and decreased the microcrystalline thickness from 2.34 to 1.57 nm. The specific surface area of EAC-3 and AC-5 was 3461 and 3291 m2⋅g-1, respectively. The average pore size of EAC-3 was 2.19 nm, which is 0.11 nm larger than that of AC-5. At a scan rate of 0.5 mV⋅s-1, EAC-3 and AC-5 achieved a specific gravimetric capacitance of 486 and 429 F⋅g-1, respectively. Supercapacitor based on EAC-3 possessed lower resistance and better power performance.


2018 ◽  
Vol 10 (3) ◽  
pp. 149
Author(s):  
Mahmud Sudibandriyo ◽  
L Lydia

Surface area characterization of activated carbon from sugarcane baggase by chemical activationAdsorption is one the process with many applications in the industries such as in a separation or in gas storage. In this adsorption, adsorbent selection is the most important thing. One of the adsorbent most suitable for this process is activated carbon. Previous studies show that high surface area of activated carbon can be produced from sugarcane bagasse using activator ZnCl2. The research’s goal is to produce activated carbon from sugarcane bagasse and determine the effects of activator on the surface area of activated carbon produced. Activators used in this research are KOH and ZnCl2 with the mass ratio of activator/carbon are 1/1, 2/1 and 3/1. The results show that The highest surface area, 938,2 m2/g, is obtained by activation using KOH with mass ratio of activator/carbon 3/1, whereas the highest surface area by activation using ZnCl2 is 632 m2/g with mass ratio of activator/carbon 2/1. For comparison, preparation of activated carbon by physical activation is also done and the surface area is 293 m2/g.Keywords: Activated carbon, chemical activation, sugarcane bagasse, KOH, ZnCl2 Abstrak Adsorpsi merupakan salah satu proses yang banyak digunakan dalam industri baik dalam pemisahan maupun untuk penyimpanan gas. Pada proses adsorpsi ini, pemilihan adsorben merupakan hal yang sangat penting. Salah satu jenis adsorben yang sangat cocok untuk proses ini adalah karbon aktif. Penelusuran studi sebelumnya menunjukkan bahwa karbon aktif dengan luas permukaan yang cukup tinggi dapat dibuat dari ampas tebu dengan menggunakan aktivator ZnCl2. Penelitian ini bertujuan untuk menghasilkan karbon aktif dari ampas tebu dengan aktivasi kimia serta mengetahui pengaruh aktivator terhadap luas permukaan karbon aktif yang dihasilkan. Aktivator yang digunakan dalam penelitian ini adalah KOH dan ZnCl2 dengan rasio massa aktivator/massa karbon 1/1, 2/1, dan 3/1. Aktivasi dilakukan pada temperatur 700 oC selama 1 jam. Hasil penelitian menunjukkan bahwa luas permukaan tertinggi sebesar 938,2 m2/g diperoleh dengan aktivasi menggunakan KOH dengan rasio massa aktivator/massa arang 3/1, sedangkan aktivasi dengan menggunakan ZnCl2 diperoleh luas permukaan tertinggi sebesar 632 m2/g dengan rasio massa aktivator/massa arang 2/1. Sebagai pembanding, pada penelitian ini juga dilakukan pembuatan karbon aktif dengan metode aktivasi fisika dan diperoleh luas permukaan karbon aktif sebesar 293 m2/g.Kata kunci: Aktivasi kimia, ampas tebu, karbon aktif, KOH, ZnCl2


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