Two-Dimensional Phosphorene-Derived Protective Layers on a Lithium Metal Anode for Lithium-Oxygen Batteries

Kim, Youngjin,Koo, Dongho,Ha, Seongmin,Jung, Sung Chul,Yim, Taeeun,Kim, Hanseul,Oh, Seung Kyo,Kim, Dong-Min,Choi, Aram,Kang, Yongku,Ryu, Kyoung Han,Jang, Minchul,Han, Young-Kyu,Oh, Seung M.,Lee, Kyu T American Chemical Society 2018 ACS NANO Vol.12 No.5

<P>Lithium-oxygen (Li-O<SUB>2</SUB>) batteries are desirable for electric vehicles because of their high energy density. Li dendrite growth and severe electrolyte decomposition on Li metal are, however, challenging issues for the practical application of these batteries. In this connection, an electrochemically active two-dimensional phosphorene-derived lithium phosphide is introduced as a Li metal protective layer, where the nanosized protective layer on Li metal suppresses electrolyte decomposition and Li dendrite growth. This suppression is attributed to thermodynamic properties of the electrochemically active lithium phosphide protective layer. The electrolyte decomposition is suppressed on the protective layer because the redox potential of lithium phosphide layer is higher than that of electrolyte decomposition. Li plating is thermodynamically unfavorable on lithium phosphide layers, which hinders Li dendrite growth during cycling. As a result, the nanosized lithium phosphide protective layer improves the cycle performance of Li symmetric cells and Li-O<SUB>2</SUB> batteries with various electrolytes including lithium bis(trifluoromethanesulfonyl)imide in <I>N,N</I>-dimethylacetamide. A variety of <I>ex situ</I> analyses and theoretical calculations support these behaviors of the phosphorene-derived lithium phosphide protective layer.</P> [FIG OMISSION]</BR>

Autoxidation in amide-based electrolyte and its suppression for enhanced oxygen efficiency and cycle performance in non-aqueous lithium oxygen battery

Kim, Dong Wook,Lee, Dong Hun,Ahn, Su Mi,Kim, Do Youb,Suk, Jungdon,Choi, Dong Hoon,Kang, Yongku Elsevier 2017 Journal of Power Sources Vol.347 No.-

<P><B>Abstract</B></P> <P>In spite of several desirable properties such as high stability against superoxide anion and low vapor pressure, <I>N</I>-methyl-2-pyrrolidone (NMP) electrolyte is reported not suitable for use in lithium-oxygen (Li-O<SUB>2</SUB>) batteries because of severe degradation upon cycling and low oxygen efficiency. In this work, we find that NMP electrolyte is reactive with O<SUB>2</SUB> gas in the presence of lithium metal and such O<SUB>2</SUB>-consuming reaction (<I>i.e.,</I> autoxidation) is a possible cause for the poor performance in Li-O<SUB>2</SUB> batteries with NMP electrolyte. The autoxidation of NMP is verified by direct measurement of the depletion of O<SUB>2</SUB> gas in the hermetically sealed symmetric Li/Li cells via in-situ gas pressure analysis. In-situ differential electrochemical mass spectroscopy (DEMS) experiment reveals that the autoxidation resulted in significant O<SUB>2</SUB> consumption upon discharge, very low O<SUB>2</SUB> efficiency upon charge, and eventually fast capacity fading. Lithium nitrate (LiNO<SUB>3</SUB>), which provides a protective layer on the surface of lithium metal, is employed to suppress the autoxidation, leading to significantly enhanced oxygen efficiency and cycle life.</P> <P><B>Highlights</B></P> <P> <UL> <LI> NMP electrolyte is reactive with O<SUB>2</SUB> gas in the presence of lithium metal. </LI> <LI> Autoxidation is verified by in-situ gas pressure analysis and DEMS. </LI> <LI> Autoxidation results in low O<SUB>2</SUB> efficiency and fast capacity fading. </LI> <LI> LiNO<SUB>3</SUB> is employed to suppress the autoxidation. </LI> <LI> LiNO<SUB>3</SUB> is efficient in enhancing oxygen efficiency and cycle life. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A Dual-phasic Carbon Composite Cathode for Lithium-Oxygen Batteries

( Pham Thi Thu Hien ),김영수,이종원,박민식 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

Lithium-oxygen batteries have been attracting a lot of interest due to their extremely huge theoretical capacity. Lithium ion from the anode is combined with reduced oxygen and form lithium peroxide (Li₂O₂) at the cathode during the discharge. Li₂O₂ is stored there and later convert back to lithium ion and oxygen during the charge. Therefore, the cathode should have large surface area to provide abundant reaction sites and large volume to accommodate as much Li₂O₂ as possible. It also should be porous for oxygen transport facilitation and good at electric conductivity. Herein, we propose a dual-phasic carbon composite that exploits the synergy between metal-organic frameworks (MOFs) and carbon nanotubes (CNTs). The dual-phasic nanoarchitecture incorporates the advantages of both components: MOF-C provides a large surface area and a large pore volume for Li₂O₂ storage, and CNTs provide facile pathways for electron and O₂ transport as well as additional spaces for Li₂O₂ storage.

산소 발생 효율 분석에 의한 리튬공기전지에 적합한 금속 할라이드 레독스 매개체의 선별

김주형,김동욱 한국전지학회 2024 한국전지학회지 Vol.4 No.1

본 논문에서는 in-situ differential electrochemical mass spectroscopy(in-situ DEMS)로 충전과정에서의 산소발생효율 을 실시간 정량 분석하여 리튬공기전지에 보다 적합한 금속 할라이드 촉매를 선별하기 위한 연구를 진행하였다. 금속 양 이온은 리튬공기전지의 에너지 효율 및 산소발생효율에 미치는 영향은 미미한 것으로 확인되었다. 전해액 용매는 약간의 영향이 있음을 확인하였으나, 음이온의 종류는 리튬공기전지의 성능에 가장 큰 영향을 주었다. Bromine계 촉매가 iodine 계에 비하여 에너지 효율이 2% 정도 낮은 경향을 보였지만, 산소발생효율은 20% 이상 높아 리튬공기전지에 보다 적합하 였다. 충전과정에서 발생하는 수소기체를 정량분석한 결과, bromine계 전해액은 iodine계에 비하여 리튬 음극에 훨씬 높 은 안정성을 발현하였다. 이와 같은 안정성이 bromine계 촉매의 성능 향상에 중요한 요인이 되었다. In this paper, in-situ differential electrochemical mass spectroscopy (in-situ DEMS) was used to evaluate oxygen evolution efficiency at charge in quantitative and real-time manner to select more suitable metal halide for high performance lithium air battery. The results showed that metal cations had a minimal effect on the performance. Although electrolyte solvent had some effect on the performance, halide anion showed the highest impact on the performance. Bromine catalysts showed a little lower energy efficiency of approximately 2% than iodine catalysts, but, the former showed much larger oxygen evolution efficiency of more than 20% than the latter, indicating that the bromine catalysts are found more suitable for high performance lithium air battery. Hydrogen gas evolution efficiency at charge indicated that the bromine catalysts were more stable in contact with lithium anode than iodine ones. Such stability is considered key factor for the high performance of the bromine catalysts.

Facile synthesis of mesoporous and highly nitrogen/sulfur dual‑doped graphene and its ultrahigh discharge capacity in non‑aqueous lithium oxygen batteries

Seokhoon Jang,Jieun Kim,Eunbeen Na,Mingyu Song,Jinkyu Choi,KyongHwa Song,Sung‑Hyeon Baeck,Sang Eun Shim 한국탄소학회 2019 Carbon Letters Vol.29 No.3

High-level heteroatom, N and S, dual-doped graphene with an improved mesoporous structure was fabricated via facile in situ carbonization and used as metal-free cathode for non-aqueous lithium oxygen batteries. The prepared cathode delivered an ultrahigh specific capacity of 22,252 mAh/g at a current density of 200 mA/g as well as better cycling reversibility because of the larger and copious mesopores, which can promote the penetration of oxygen, electrons, and lithium ions and the ability to accommodate more discharge products, e.g., Li2O2, in Li–O2 batteries. The material had a high level of heteroatom co-doping in the carbon lattice, which enhanced the electrical conductivity and served as active sites for the oxygen reduction reaction.

Role of solvents on the oxygen reduction and evolution of rechargeable Li-O₂ battery

Christy, Maria,Arul, Anupriya,Zahoor, Awan,Moon, Kwang Uk,Oh, Mi Young,Stephan, A. Manuel,Nahm, Kee Suk Elsevier 2017 Journal of Power Sources Vol.342 No.-

<P><B>Abstract</B></P> <P>The choice of electrolyte solvent is expected to play a key role in influencing the lithium-oxygen battery performance. The electrochemical performances of three electrolytes composed of lithium bis (trifluoromethane sulfonyl) imide (LiTFSI) salt and different solvents namely, ethylene carbonate/propylene carbonate (EC/PC), tetra ethylene glycol dimethyl ether (TEGDME) and dimethyl sulfoxide (DMSO) are investigated by assembling lithium oxygen cells. The electrolyte composition significantly varied the specific capacity of the battery. The choice of electrolyte also influences the overpotential, cycle life, and rechargeability of the battery. Electrochemical impedance spectra, cyclic voltammetry, and chronoamperometry were utilized to determine the reversible reactions associated with the air cathode.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The choice of electrolyte solvent influences the lithium/O<SUB>2</SUB> battery performance. </LI> <LI> Three solvents; TEGDME, ECPC and DMSO exhibit proper reversible reaction. </LI> <LI> TEGDME demonstrate a comparatively suitable electrode – electrolyte combination. </LI> </UL> </P>

A Mo₂C/Carbon Nanotube Composite Cathode for Lithium–Oxygen Batteries with High Energy Efficiency and Long Cycle Life

Kwak, Won-Jin,Lau, Kah Chun,Shin, Chang-Dae,Amine, Khalil,Curtiss, Larry A,Sun, Yang-Kook American Chemical Society 2015 ACS NANO Vol.9 No.4

<P>Although lithium oxygen batteries are attracting considerable attention because of the potential for an extremely high energy density, their practical use has been restricted owing to a low energy efficiency and poor cycle life compared to lithium-ion batteries. Here we present a nanostructured cathode based on molybdenum carbide nanoparticles (Mo2C) dispersed on carbon nanotubes, which dramatically increase the electrical efficiency up to 88% with a cycle life of more than 100 cycles. We found that the Mo2C nanoparticle catalysts contribute to the formation of well-dispersed lithium peroxide nanolayers (Li2O2) on the Mo2C/carbon nanotubes with a large contact area during the oxygen reduction reaction (ORR). This Li2O2 structure can be decomposed at low potential upon the oxygen evolution reaction (OER) by avoiding the energy loss associated with the decomposition of the typical Li2O2 discharge products.</P>

A dual membrane composed of composite polymer membrane and glass fiber membrane for rechargeable lithium-oxygen batteries

Woo, Hyun-Sik,Kim, Jae-Hong,Moon, Yong-Bok,Kim, Won Keun,Ryu, Kyoung Han,Kim, Dong-Won Elsevier 2018 Journal of membrane science Vol.550 No.-

<P><B>Abstract</B></P> <P>Development of the lithium ion-conducting membrane with high ionic conductivity and good interfacial stability is a major challenge for lithium-oxygen batteries with high energy density. Herein, we design the dual membrane composed of Li<SUP>+</SUP> ion-conducting ceramic-based composite polymer membrane and glass fiber membrane. The optimized membrane exhibited a high ionic conductivity of 8.1 × 10<SUP>−4</SUP> Scm<SUP>−1</SUP> at ambient temperature and retained an electrolyte solution well in the membrane. The dual membrane also effectively suppressed the lithium dendrite growth and blocked superoxide anion radical attack toward polymer in the composite polymer membrane. The lithium-oxygen cell employing dual membrane exhibited improved cycle life (> 70 cycles) at a constant current density of 0.1mAcm<SUP>−2</SUP>, which was much better than the cell with either a composite polymer membrane alone or a glass fiber membrane alone.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Dual membrane is prepared with composite polymer membrane and glass fiber membrane. </LI> <LI> The dual membrane suppresses dendrite growth and exudation of liquid electrolyte. </LI> <LI> The lithium-oxygen cell assembled with dual membrane exhibits good cycling stability. </LI> </UL> </P>

Amine‑functionalized graphene and its high discharge capacity for non‑aqueous lithium–oxygen batteries

Eunbeen Na,Jieun Kim,Minjae Kim,Seokhoon Jang,Mingyu Song,KyongHwa Song,Sung‑Hyeon Baeck,Sang Eun Shim 한국탄소학회 2019 Carbon Letters Vol.29 No.5

Amine-functionalized graphene was synthesized via a one-step solvothermal method and used as a metal-free cathode for non-aqueous lithium–oxygen batteries. The material delivered an outstanding specific capacity of 19,789 mAh/g at a current density of 200 mA/g as well as better cycling stability than graphene without the amine functional group. This improvement was attributed to the electron-donating effect of the amine groups and appropriate mesopore volume, which can promote the penetration of oxygen, electrons, and lithium ions, as well as accommodate more discharge products, Li2O2 in Li–O2 batteries. Amine-functionalized graphene has an amine functional group on the carbon surface, which improves the electrical conductivity of carbon and provides electrochemical active sites for oxygen absorption reactions.

Technical issues and recent progress in metal-air batteries

이종원,정규남 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

In recent years, there has been a strong demand for advanced rechargeable battery systems with high energy storage capability. Among the various energy storage technologies under development, a metal-air battery, in which a metal anode (Li, Zn, etc.) is coupled with an air-breathing porous cathode, delivers much higher specific energy compared to conventional battery chemistries such as lithium-ion batteries. During discharge, the metal-air battery generates electricity through an oxidation reaction of a metal anode and a reduction reaction of oxygen (O2) on a porous cathode. The reverse reactions occur upon charge. This talk introduces the technical challenges facing development of metal-air batteries with specific attention to electrochemistry and materials, and then presents promising strategies to designing electrodes and electrolytes that could improve a battery`s capacity, energy efficiency, rate-capability, and cyclability.