• Title, Summary, Keyword: Electrolyte Additive

Search Result 116, Processing Time 0.032 seconds

Effect of Lithium Bis(Oxalato)Borate Additive on Thermal Stability of Si Nanoparticle-based Anode (리튬 이차 전지용 실리콘 나노입자 음극의 고온 열안정성에 대한 Lithium bis(oxalato)borate첨가제의 효과)

  • Kim, Min-Jeong;Choi, Nam-Soon;Kim, Sung-Soo
    • Journal of the Korean Electrochemical Society
    • /
    • v.17 no.2
    • /
    • pp.79-85
    • /
    • 2014
  • Silicon (Si) has been investigated as promising negative-electrode (anode) materials because its theoretical specific capacity of 4200 mAh/g for $Li_{4.4}Si$ is far higher than that of carbonaceous anodes in current commercial products. However, in practice, the application of Si to Li-ion batteries is still quite challenging because Si suffers from severe volume expansion and contraction and lead to a continuous solid electrolyte interphase (SEI)-filming process by cracking of Si. This process consumes the limited $Li^+$ source, builds up thick and unstable SEI layer on the Si active materials, and will eventually disable the cell. Since unstable SEI reduces electrochemical performance and thermal stability of the Si anode, the surface chemistry of the anode should be modified by using a functional additive. It is found that lithium bis(oxalato)borate (LiBOB) as an additive effectively protected the Si anode surface, improved capacity retention when stored at $60^{\circ}C$, and alleviated exothermic thermal reactions of fully lithiated Si anode.

Effect of Additives on the Hardness of Copper Electrodeposits in Acidic Sulfate Electrolyte (황산구리 전착에서의 첨가제가 구리전착층의 경도에 미치는 영향)

  • Min, Sung-Ki;Lee, Jeong-Ja;Hwang, Woon-Suk
    • Corrosion Science and Technology
    • /
    • v.10 no.4
    • /
    • pp.143-150
    • /
    • 2011
  • Copper electroplating has been applied to various fields such as decorative plating and through-hole plating. Technical realization of high strength copper preplating for wear-resistant tools and molds in addition to these applications is the aim of this work. Brighters and levelers, such as MPSA, Gelatin, Thiourea, PEG and JGB, were added in copper sulfate electrolyte, and the effects of these organic additives on the hardness were evaluated. All additives in this work were effective in increasing the hardness of copper electrodeposits. Thiourea increased the hardness up to 350 VHN, and was the most effective accelarator in sulfate electrolyte. It was shown from the X-ray diffraction analysis that preferred orientation changed from (200) to (111) with increasing concentration of organic additives. Crystallite size decreased with increasing concentration of additive. Hardness was increased with decreasing crystallite size, and this result is consistent with Hall-Petch relationship, and it was apparent that the hardening of copper electrodeposits results from the grain refining effect.

Conducting and interface characterization of carbonate-type organic electrolytes containing EMImBF4 as an additive against activated carbon electrode

  • Kim, Mingyeong;Kim, Kyungmin;Kim, Seok
    • Carbon letters
    • /
    • v.16 no.1
    • /
    • pp.51-56
    • /
    • 2015
  • Carbonate-type organic electrolytes were prepared using propylene carbonate (PC) and dimethyl carbonate (DMC) as a solvent, quaternary ammonium salts, and by adding different contents of 1-ethyl-3-methyl imidazolium tetrafluoroborate ($EMImBF_4$). Cyclic voltammetry and linear sweep voltammetry were performed to analyze conducting behaviors. The surface characterizations were analyzed by scanning electron microscopy method and X-ray photoelectron spectroscopy. From the experimental results, increasing the $EMImBF_4$ content increased the ionic conductivity and reduced bulk resistance and interfacial resistance. In particular, after adding 15 vol% $EMImBF_4$ in 0.2 M $SBPBF_4$ PC/DMC electrolyte, the organic electrolyte showed superior capacitance and interfacial resistance. However, when $EMImBF_4$ content exceeded 15 vol%, the capacitance was saturated and the voltage range decreased.

Characteristics of the Zn-Br Redox Flow Battery using the Different Electrolyte and Membrane (전해액과 격막에 따른 Zn-Br 레독스 흐름 전지의 특성)

  • CHOI, HO-SANG;OH, YONG-HWAN;RYU, CHEOL-HWI;HWANG, GAB-JIN
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.27 no.4
    • /
    • pp.365-371
    • /
    • 2016
  • Cell performance of the Zn-Br redox flow battery (ZBRFB) using two different type's membrane (Nafion117 and SF-600) was evaluated at $20mA/cm^2$ of current density in 1M (mol/L) $ZnBr_2$ + 2M KCl + 0.3M EMPBr(1-ethyl-1-methyl pyrrolidinium bromide) electrolyte. The average energy efficiencies of ZBRFB were 74.9% and 74.7% for Nafion117 and SF-600, respectively. The electrolyte added the 1-ethyl-3-methylimidazolium dicyanamide (EMICA) as an additive was tested for the electrolyte in ZBRFB using SF-600 at $30mA/cm^2$ of current density. An average energy efficiency of the ZBRFB was 74.5% and 77.4% for the electrolyte non-added EMICA and added 1wt% of EMICA, respectively. ZBRFB using the electrolyte added EMICA was showed the higher performance than that using the electrolyte non-added EMICA.

Effect of Lithium Bis(oxalate)borate as an Electrolyte Additive on Carbon-coated SiO Negative Electrode (탄소가 코팅된 일산화규소(SiO) 음극에서 전해질 첨가제로서 Lithium Bis(oxalato)borate의 영향)

  • Kim, Kun Woo;Lee, Jae Gil;Park, Hosang;Kim, Jongjung;Ryu, Ji Heon;Kim, Young-Ugk;Oh, Seung M.
    • Journal of the Korean Electrochemical Society
    • /
    • v.17 no.1
    • /
    • pp.49-56
    • /
    • 2014
  • As an electrolyte additive, the effects of lithium bis(oxalate)borate (LiBOB) on the electrochemical properties of a carbon-coated silicon monoxide (C-coated SiO) negative electrode are investigated. The used electrolyte is 1.3M $LiPF_6$ that is dissolved in ethylene carbonate (EC), fluoroethylene carbonate (FEC), and diethyl carbonate (DEC) (5:25:70 v/v/v) with or without 0.5 wt. % LiBOB. In the LiBOB-free electrolyte, the film resistance is not so high in the initial period of cycling that lithiation is facilitated to generate the crystalline $Li_{15}Si_4$ phase. Due to repeated volume change that is caused by such a deep charge/discharge, cracks form in the active material to cause a resistance increase, which eventually leads to capacity fading. When LiBOB is added into the electrolyte, however, more resistive surface film is generated by decomposition of LiBOB in the initial period. The crystalline $Li_{15}Si_4$ phase does not form, such that the volume change and crack formation are greatly mitigated. Consequently, the C-coated SiO electrode exhibits a better cycle performance in the later cycles. At an elevated temperature ($45^{\circ}C$), wherein the effect of film resistance is less critical, the alloy ($Li_{15}Si_4$ phase) formation is comparable for the LiBOB-free and added cell to give a similar cycle performance.

Thermal and Electrochemical Studies of Tris(2,4,6-trimethoxyphenyl)Phosphine as a Flame Retardant Additive for Li-ion Battery (리튬이차전지 난연성 전해액 첨가제로서의 Tris(2,4,6-trimethoxyphenyl)Phosphine의 열적, 전기화학적 특성)

  • Ahn, Se-Young;Kim, Ke-Tack;Kim, Hyun-Soo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.21 no.12
    • /
    • pp.1130-1134
    • /
    • 2008
  • Thermal and electrochemical properties were discussed with tris(2,4,6-trimethoxyphenyl)Phosphine (TTMPP) as a flame retradant additive for Li-ion battery. TTMPP showed excellent thermal stability with charged cathodes. Addition of 1 wt.% of the additive to the electrolyte improved the thermal stability without damaging the performance of the battery. The oxygne evolution reaction delayed nearly by $60^{\circ}C$. The capacity retention ratio in cycle life tests of the battery with 1 wt.% TTMPP was slightly improved comparing to the no additive cells.

Synthesis and Electrochemical Characteristics of Silicon/Carbon Anode Composite with Binders and Additives (Silicon/Carbon 음극소재 제조 및 바인더와 첨가제에 따른 전기화학적 특성)

  • Park, Ji Yong;Lee, Jong Dae
    • Korean Chemical Engineering Research
    • /
    • v.56 no.3
    • /
    • pp.303-308
    • /
    • 2018
  • Silicon/Carbon (Si/C) composite as anode materials for lithium-ion batteries was synthesized to find the effect of binders and an electrolyte additive. Si/C composites were prepared by two step method, including magnesiothermic reduction of SBA-15 (Santa Barbara Amorphous material No. 15) and carbonization of phenol resin. The electrochemical performances of Si/C composites were investigated by charge/discharge, cyclic voltammetry and impedance tests. The anode electrode of Si/C composite with PAA binder appeared better capacity (1,899 mAh/g) and the capacity retention ratio (92%) than that of other composition coin cells during 40 cycles. Then, Vinylene carbonate (VC) was tested as an electrolyte additive. The influence of this additive on the behavior of Si/C anodes was very positive (3,049 mAh/g), since the VC additive is formed passivation films on Si/C surfaces and suppresses irreversible changes.

Electrochemical Behaviors of the Surface-Treated Nickel Hydroxide Powder and Electrolyte Additive LiGH for Ni-MH Batteries (니켈수소전지용 수산화니켈 입자의 표면처리와 전해액 첨가제 LiOH의 전기화학적 거동)

  • Kim, Ho-Sung;Oh, Ik-Hyun
    • Journal of the Korean Electrochemical Society
    • /
    • v.11 no.2
    • /
    • pp.115-119
    • /
    • 2008
  • Single particle of nickel hydroxide and the surface-treated one with cobalt element were performed to review the effect of LiOH additive in alkaline electrolyte for Ni-MH batteries using microelectrode test system. As a result of cyclic voltammetry, the electrochemical behaviors such as the oxidation/reduction and oxygen evolution reaction are clearly observed for a single particle of nickel hydroxide, respectively. Furthermore, the reduction current peak of nickel hydroxide added with LiOH in electrolyte was very low and broad compared with the normal nickel hydroxide without an additive LiOH, which had a bad effect to the crystallization structure of nickel hydroxide. However, it was found that capacity and cycle properties of the nickel hydroxide treated with cobalt greatly increased by the addition of LiOH.

Synthesis and Characteristics of Acrylol Borate as New Acrylic Gelator for Lithium Secondary Battery

  • Shin, Hyun-Min;Nguyen, Congtranh;Kim, Byeong-Yeol;Han, Myong-Hee;Kim, Ju-Sung;Kim, Jin-Hwan
    • Macromolecular Research
    • /
    • v.16 no.2
    • /
    • pp.134-138
    • /
    • 2008
  • A novel acrylol borate was designed and synthesized by reacting acrylate monomer and boric acid. The obtained acrylol borate was used as both gelator and anion receptor for the liquid electrolyte in a lithium secondary battery. It was found that the ionic conductivity of the gel polymer electrolyte (GPE) was as high as that of the liquid electrolyte, and the thermal stability of GPE was increased when only 2 wt% acrylol borate was incorporated into the liquid electrolyte. These results suggest that acrylol borate can be used as an effective additive to enhance the thermal stability of the electrolyte without adversely affecting its conductivity. It is believed that the strong complex formation between boron in the gelator and the anion of the salt is responsible for the enhanced thermal stability of the electrolyte solution and the increased ionic conductivity.

Effect of Vinylene Carbonate as an Electrolyte Additive on the Electrochemical Properties of Micro-Patterned Lithium Metal Anode (미세 패턴화된 리튬금속 전극의 Vinylene Carbonate 첨가제 도입에 따른 전기화학 특성에 관한 연구)

  • Jin, Dahee;Park, Joonam;Dzakpasu, Cyril Bubu;Yoon, Byeolhee;Ryou, Myung-Hyun;Lee, Yong Min
    • Journal of the Korean Electrochemical Society
    • /
    • v.22 no.2
    • /
    • pp.69-78
    • /
    • 2019
  • Lithium metal anode with the highest theoretical capacity to replace graphite anodes are being reviewed. However, the dendrite growth during repeated oxidation/reduction reaction on lithium metal surface, which results in poor cycle performance and safety issue has hindered its successful implementation. In our previous work, we solved this problem by using surface modification technique whereby a surface pattern on lithium metal anode is introduced. Although the micro-patterned Lithium metal electrode is beneficial to control Li metal deposition efficiently, it is difficult to control the mossy-like Li granulation at high current density ($>2.0mA\;cm^{-2}$). In this study, we introduce vinylene carbonate (VC) electrolyte additive on micro patterned lithium metal anode to suppress the lithium dendrite growth. Owing to the synergetic effect of micro-patterned lithium metal anode and VC electrolyte additive, lithium dendrite at a high current density is dense. As a result, we confirmed that the cycle performance was further improved about 6 times as compared with the reference electrode.