• Title, Summary, Keyword: Electrolyte Additive

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Effects of the Mixing of an Active Material and a Conductive Additive on the Electric Double Layer Capacitor Performance in Organic Electrolyte

  • Yang, Inchan;Kwon, Soon Hyung;Kim, Bum-Soo;Kim, Sang-Gil;Lee, Byung-Jun;Kim, Myung-Soo;Jung, Ji Chul
    • Korean Journal of Materials Research
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    • v.25 no.3
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    • pp.132-137
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    • 2015
  • The effects of the mixing of an active material and a conductive additive on the electrochemical performance of an electric double layer capacitor (EDLC) electrode were investigated. Coin-type EDLC cells with an organic electrolyte were fabricated using the electrode samples with different ball-milling times for the mixing of an active material and a conductive additive. The ball-milling time had a strong influence on the electrochemical performance of the EDLC electrode. The homogeneous mixing of the active material and the conductive additive by ball-milling was very important to obtain an efficient EDLC electrode. However, an EDLC electrode with an excessive ball-milling time displayed low electrical conductivity due to the characteristic change of a conductive additive, leading to poor electrochemical performance. The mixing of an active material and a conductive additive played a crucial role in determining the electrochemical performance of EDLC electrode. The optimal ball-milling time contributed to a homogeneous mixing of an active material and a conductive additive, leading to good electrochemical performance of the EDLC electrode.

Effect of Fluoroethylene Carbonate in the Electrolyte for LiNi0.5Mn1.5O4 Cathode in Lithium-ion Batteries

  • Kim, Jaemin;Go, Nakgyu;Kang, Hyunchul;Tron, Artur;Mun, Junyoung
    • Journal of Electrochemical Science and Technology
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    • v.8 no.1
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    • pp.53-60
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    • 2017
  • Fluoroethylene carbonate (FEC) was studied as an additive for the electrolyte in lithium ion batteries with the $LiNi_{0.5}Mn_{1.5}O_4$ (LNMO) spinel cathode operating at a high potential beyond 4.7 V (vs. $Li/Li^+$). It was found that the FEC additive was electrochemically active for the $1^{st}$ charge cycle on the LNMO cathode. The presence of a large amount of FEC (more than 40 vol%) in the electrolyte caused severe side reactions with abnormally long voltage plateaus. In contrast, when the electrolyte contained less than 30 vol% FEC, the surface of the LNMO cathode was stabilized by the formation of the solid-electrolyte interphase (SEI), leading to improved cyclability. However, the resistance from the SEI limited the rate capability because of sluggish lithium transportation through the SEI and electronic insulation between the particles in the electrode.

A Study on the Electrochemical Properties for Effect of Additive of the Lithium Metal Anode (리튬 금속 음극의 첨가제 효과에 따른 전기 화학적 특성에 관한 연구)

  • Cho, S.M.;Lee, S.W.;Cho, B.W.;Ju, J.B.;Sohn, T.W.
    • Journal of the Korean Electrochemical Society
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    • v.5 no.3
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    • pp.159-163
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    • 2002
  • The use of lithium metal anode at lithium metal secondary battery can provide the very high energy density. Nevertheless, there are some problems that are short cycle life, lack of safety and poor thermal stability. Cycle life and cycling efficiency decline due to passivating films, dendritic lithium and increasing surface film by the reaction of lithium metal and electrolyte. This work investigated the additive effect of benzene, toluene, tetram-ethylethylenediamine, into the electrolyte. The cycling efficiency and cyclability are improved. The reason is confirmed by decreasing film resistance and increasing polarization resistance at AC impedance analysis. Electrolyte additive has a relatively less reactivity than electrolytes lithium and is adsorbed on lithium leading to suppression of the reaction between the electrolyte and lithium as well as an improvement in the lithium deposition mophology.

Organic Solvents Containing Zwitterion as Electrolyte for Li Ion Cells

  • Krishnan, Jegatha Nambi;Kim, Hyung-Sun;Lee, Jae-Kyun;Cho, Byung-Won;Roh, Eun-Joo;Lee, Sang-Gi
    • Bulletin of the Korean Chemical Society
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    • v.29 no.9
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    • pp.1705-1710
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    • 2008
  • Imidazolium based zwitterions, 1,2-dimethylimidazolium-3-n-propanesulfonate (DMIm-3S) and 1-Butylimidazolium-3-n-butanesulphonate (BIm-4S), were synthesized, and utilized them as additive for Li ion cell comprising of graphite anode and $LiCoO_2$ cathode. The use of 10 wt% of DMIm-3S in 1 M $LiPF_6$, EC-EMCDMC (1:1:1 (v/v)) resulted in the increased high rate charge-discharge performance. The low temperature performance of the Li ion cells at about −20 ${^{\circ}C}$ was also enhanced by these zwitterion additives. The DMIm- 3S additive resulted in the better capacity retention by the Li-ion cells even after 120 cycles with 100% depth of discharge (DOD) at 1 C rate in room temperature. Surface morphology of both graphite and $LiCoO_2$ electrode before and after 300 cycles was studied by scanning electron microscopy. An analogous study was performed using liquid electrolyte without any additive.

A Density Functional Theory Study of Additives in Electrolytes of a Dye Sensitized Solar Cell

  • Lee, Maeng-Eun;Kang, Moon-Sung;Cho, Kwang-Hwi
    • Bulletin of the Korean Chemical Society
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    • v.34 no.8
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    • pp.2491-2494
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    • 2013
  • The effect of additives in an electrolyte solution on the conversion efficiency of a dye sensitized solar cell was investigated. A density functional theory (DFT) method was used to examine the physical and chemical properties of nitrogen-containing additives adsorbed on a $TiO_2$ surface. Our results show that additives which cause lower partial charges, higher Fermi level shifts, and greater adsorption energies tend to improve the performance of DSSCs. Steric effects that prevent energy losses due to electron recombination were also found to have a positive effect on the conversion efficiency. In this work, 3-amino-5-methylthio-1H-1,2,4-triazole (AMT) has been suggested as a better additive than the most popular additive, TBP, and verified with experiments.

Effect of Tris(trimethylsilyl) Phosphate Additive on the Electrochemical Performance of Nickel-rich Cathode Materials at High Temperature

  • Jang, Seol Heui;Mun, Junyoung;Kang, Dong-Ku;Yim, Taeeun
    • Journal of Electrochemical Science and Technology
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    • v.8 no.2
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    • pp.162-168
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    • 2017
  • $LiNi_xCo_yMn_zO_2$ cathode materials have been the focus of much attention because of their high specific capacity. However, because of the poor interfacial stability between cathodes and electrolytes, the cycling performance of these materials fades rapidly, especially at high temperatures. In the present paper, we propose the use of tris(trimethylsilyl) phosphate (TMSPO), which contains phosphate and silyl functional groups, as a functional additive in electrolytes. The addition of TMSPO resulted in the formation of cathode electrolyte interphase (CEI) layers on the surfaces of the cathodes and effectively suppressed electrolyte decomposition reactions, even at high temperatures. As a result, cells cycled with TMSPO exhibited remarkable capacity, which remained after 50 cycles (82.0%), compared to cells cycled without TMSPO (64.6%).

Effect of Oral Administration of DiakurTM (a Glucose and Electrolytes Additive) on Growth and Some Physiological Responses in Broilers Reared in a High Temperature Environment

  • Takahashi, Kazuaki;Akiba, Yukio
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.9
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    • pp.1341-1347
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    • 2002
  • An experiment was conducted to determine effects of oral administration of $Diakur^{TM}$ (an additive of glucose and electrolytes for young calves) on growth performance and some physiological responses in male broilers reared in a high temperature. A 2 by 3 factorial arrangement test of 2 temperatures (24 and $36^{\circ}C$) and 3 levels of oral administration of the glucose and electrolytes additive, $Diakur^{TM}$, (0, 150 and 300 mg/day/100 gBW) were applied in the experiment. Male broiler chicks (2 weeks of age) were assigned to six groups and received dietary and temperature treatments for 7 days. The additive of glucose and electrolytes was suspended with water and intubated into crop twice a day (08:00 and 17:00). Oral administration of the additive prevented decreases in food intake and growth rates in broilers due to exposure of the hot environment. Oral administration of the additive also improved a lowered electrolyte ($Na^+$ + $K^+$ - $Cl^-$) balance in plasma, low mitogenic response of blood mononuclear cell and an increase in glucose concentration due to exposure to the high environmental temperature. Oral administration of the additive increased rectal temperature regardless of environmental temperatures. On the other hand, blood pH, $pCO_2$ and $HCO_3$ - concentration, and plasma creatine kinase activity were not affected by the oral administration. The results suggested that oral administration of the glucose and electrolytes additive, $Diakur^{TM}$ during heat stress did not only prevent decrease in growth performance, but also normalized some physiological and immunological responses in male broilers.

Effects of Lithium Bis(Oxalate) Borate as an Electrolyte Additive on High-Temperature Performance of Li(Ni1/3Co1/3Mn1/3)O2/Graphite Cells (LiBOB 전해액 첨가제 도입에 따른 Li(Ni1/3Co1/3Mn1/3)O2/graphite 전지의 고온특성)

  • Jeong, Jiseon;Lee, Hyewon;Lee, Hoogil;Ryou, Myung-Hyun;Lee, Yong Min
    • Journal of the Korean Electrochemical Society
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    • v.18 no.2
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    • pp.58-67
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    • 2015
  • The effects of electrolyte additives, lithium bis(oxalate)borate (LiBOB), fluoroethylene carbonate (FEC), vinylene carbonate (VC), 2-(triphenylphosphoranylidene) succinic anhydride (TPSA), on high-temperature storage properties of $Li(Ni_{1/3}Co_{1/3}Mn_{1/3})O_2$/graphite are investigated with coin-type full cells. The 1 wt.% LiBOB-containing electrolyte showed the highest capacity retention after high temperature ($60^{\circ}C$) storage for 20 days, 86.7%, which is about 5% higher than the reference electrolyte, 1.15M lithium hexafluorophosphate ($LiPF_6$) in ethylene carbonate/ethyl methyl carbonate (EC/EMC, 3/7 by volume). This enhancement is closely related to the formation of semi-carbonate compounds originated from $BOB^-$ anions, thereby resulting in lower SEI thickness and interfacial resistance after storage. In addition, the 1 wt.% LiBOB-containing electrolyte also exhibited better cycle performance at 25 and $60^{\circ}C$ than the reference electrolyte, which indicates that LiBOB is an effective additive for high-temperature performance of $Li(Ni_{1/3}Co_{1/3}Mn_{1/3})O_2$/graphite chemistry.

Experimental Investigation on High Efficient Electrolytes of Electrochemical Photovoltaic Cells (전기화학형 광전변환 셀의 고효율 전해질 제작에 관한 실험적 고찰)

  • Kim, Doo-Hwan;Han, Chi-Hwan;Sung, Youl-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.1
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    • pp.100-104
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    • 2011
  • In this work, an optimum condition of electrolytes preparation for photovoltaic cells application was investigated experimentally in terms of impedance and conversion efficiency of the cells. 3-methoxyppropionitrie and redox pairs with LiI and $I_2$ were used as stable solvents for fabrication of electrolyte. Efficiency comparison of the prepared cells carried out for various additives and ionic liquids. From the results, there was an optimum concentration (about 0.3 M) of ionic liquids for efficient cell fabrication. For case of electrolyte using single DMAp additive, the maximum conversion efficiency of the cell was 6.4%($V_{oc}$: 0.78V, $J_{sc}$: 14.4 mA/$cm^2$, ff: 0.57). For case of electrolyte using both DMAp and CEMim additives, the maximum conversion efficiency of the cell was 7.2%($V_{oc}$: 0.79V, $J_{sc}$: 16 mA/$cm^2$, ff: 0.57). From the result of electrochemical impedance measurement, both Z1 and Z3 values of binary additives-based cell decreased compared to those of single additive-based. This is due to the decreased in internal and charge transfer resistivities of the cells.

Effect of Electrolyte Additive on the Electrochemical Characteristics of Lithium Vanadium Oxide Anode (전해질 첨가제가 리튬 바나듐 옥사이드 전극의 성능에 미치는 영향)

  • Lee, Je-Nam
    • Journal of the Korean Electrochemical Society
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    • v.21 no.3
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    • pp.55-60
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    • 2018
  • The demand for LIBs with higher energy densities has increased continuously because the emergence of wider and more challenging applications including HEV and EV has became imperative. However, in the case of anode material, graphite is insufficient to meet this need. To meet such demand, several type of negative electrode materials like silicon, tin, SiO, and transition metal oxide have been investigated for the advanced lithium secondary batteries. Recently, lithium vanadium oxide, which has a layered structure, is assumed as one of the promising anode material as alternative of graphite. This material shows a high volumetric capacity, which is 1.5 times higher than that of graphite. However, relative low electrical conductivity and particle fracture, which results in the electrolyte decomposition and loss of electric contact between electrode, induce rapid capacity decay. In this report, we investigated the effect of electrolyte additive on the electrochemical characteristics of lithium vanadium oxide.