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Electrolytes for high-energy lithium batteries
Jennifer L. Schaefer,Yingying Lu,Surya S. Moganty,Praveen Agarwal,N. Jayaprakash,Lynden A. Archer
Applied Nanoscience , 2012, DOI: 10.1007/s13204-011-0044-x
Abstract: From aqueous liquid electrolytes for lithium–air cells to ionic liquid electrolytes that permit continuous, high-rate cycling of secondary batteries comprising metallic lithium anodes, we show that many of the key impediments to progress in developing next-generation batteries with high specific energies can be overcome with cleaver designs of the electrolyte. When these designs are coupled with as cleverly engineered electrode configurations that control chemical interactions between the electrolyte and electrode or by simple additives-based schemes for manipulating physical contact between the electrolyte and electrode, we further show that rechargeable battery configurations can be facilely designed to achieve desirable safety, energy density and cycling performance.
Towards First Principles prediction of Voltage Dependences of Electrolyte/Electrolyte Interfacial Processes in Lithium Ion Batteries  [PDF]
Kevin Leung,Craig M. Tenney
Physics , 2013, DOI: 10.1021/jp408974k
Abstract: In lithium ion batteries, Li+ intercalation and processes associated with passivation of electrodes are governed by applied voltages, which are in turn associated with free energy changes of Li+ transfer (Delta G_t) between the solid and liquid phases. Using ab initio molecular dynamics (AIMD) and thermodynamic integration techniques, we compute Delta G_t for the virtual transfer of a Li+ from a LiC(6) anode slab, with pristine basal planes exposed, to liquid ethylene carbonate confined in a nanogap. The onset of delithiation, at Delta G_t=0, is found to occur on LiC(6) anodes with negatively charged basal surfaces. These negative surface charges are evidently needed to retain Li+ inside the electrode, and should affect passivation ("SEI") film formation processes. Fast electrolyte decomposition is observed at even larger electron surface densities. By assigning the experimentally known voltage (0.1 V vs. Li+/Li metal) to the predicted delithiation onset, an absolute potential scale is obtained. This enables voltage calibrations in simulation cells used in AIMD studies, and paves the way for future prediction of voltage dependences in interfacial processes in batteries.
Electronic Structure Modeling of Electrochemical Reactions at Electrode/Electrolyte Interfaces in Lithium Ion Batteries  [PDF]
Kevin Leung
Physics , 2013, DOI: 10.1021/jp308929a
Abstract: We review recent ab initio molecular dynamics studies of electrode/electrolyte interfaces in lithium ion batteries. Our goals are to introduce experimentalists to simulation techniques applicable to models which are arguably most faithful to experimental conditions so far, and to emphasize to theorists that the inherently interdisciplinary nature of this subject requires bridging the gap between solid and liquid state perspectives. We consider liquid ethylene carbonate (EC) decomposition on lithium intercalated graphite, lithium metal, oxide-coated graphite, and spinel manganese oxide surfaces. These calculations are put in the context of more widely studied water-solid interfaces. Our main themes include kinetically controlled two-electron-induced reactions, the breaking of a previously much neglected chemical bond in EC, and electron tunneling. Future work on modeling batteries at atomic lengthscales requires capabilities beyond state-of-the-art, which emphasizes that applied battery research can and should drive fundamental science development.
Li/LiFePO4 battery performance with a guanidinium-based ionic liquid as the electrolyte
XinYue Zhang,ShaoHua Fang,ZhengXi Zhang,Li Yang
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-011-4655-0
Abstract: A new guanidinium-based ionic liquid (IL) was investigated as a novel electrolyte for a lithium rechargeable battery. The viscosity, conductivity, lithium redox behavior, and charge-discharge characteristics of the lithium rechargeable batteries were investigated for the IL electrolyte with 0.3 mol kg 1 lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt. Li/LiFePO4 cells incorporating the IL electrolyte without additives showed good cycle properties at a charge-discharge current rate of 0.1 C, and exhibited good rate capabilities in the presence of a mass fraction of 10% vinylene carbonate or gamma-butyrolactone.
Progress of Non-Aqueous Electrolyte for Li-Air Batteries  [PDF]
Xianjun Liu, Baochen Cui, Shuzhi Liu, Yun Chen
Journal of Materials Science and Chemical Engineering (MSCE) , 2015, DOI: 10.4236/msce.2015.35001
Abstract: Li-air batteries have received much attention in the past several years because of their large theoretical specific energy density, stable output voltage, cost-effective, energy-efficient and pollution free, and have broad application prospects. If it is successfully developed, the battery could be an excellent energy storage device for renewable energy sources such as wind, solar, and tidal energy, which brings a prospect for human to solve the problem of environment pollution and energy crisis. But the electrolyte is a crucial component of Li-air battery and the electrochemical performance of the battery is determined by electrolyte to a great extent. Due to the react violently between lithium and water, it is not practical for Li-air battery to use directly an aqueous electrolyte unless the anode can be protected from degradation. In this review, we presented the latest research progress on the non-aqueous electrolyte, i.e. organic electrolyte, ionic liquid and solid electrolyte. We elaborated the influence of solvents, and possible additives, and/or their combination Li-air battery’s performance. Finally, we provided insights into the prospect of non-aqueous electrolyte for Li-air battery.
Preparation and Characterization of PEO―LATP/LAGP Ceramic Composite Electrolyte Membrane for Lithium Batteries
HUANG Le-Zhi, WEN Zhao-Yin, JIN Jun, LIU Yu
无机材料学报 , 2012, DOI: 10.3724/sp.j.1077.2012.00249
Abstract: A PEO―LATP/LAGP composite electrolyte for lithium batteries was designed and prepared. Uniformly composite electrolyte membrane with thickness of 20 μm was obtained by assembling Li1.4Al0.4Ti1.6(PO4)3 (LATP) or Li1.5Al0.5Ge1.5(PO4)3 (LAGP) as ceramic substrate and PEO as binder. Highest room―temperature conductivities were achieved for the sample prepared with w(ceramics):w(PEO)=7:3. Electrochemical analysis showed that the conductivity reached 0.186 mS/cm for PEO―LATP and 0.111 mS/cm for PEO―LAGP. Cycling performances of 170 mAh/g was obtained for the first discharge capacity of the Li/composite electrolyte/LiCo1/3Ni1/3Mn1/3O2 cell. Sharp decrease of cycling capacity was observed for the cell using PEO―LATP membrane. The cycling performance of the PEO―LAGP based cell was greatly improved with 150 mAh/g remained after 10 cycles.
Composite polymer electrolyte membranes supported by non-woven fabrics for lithium-ion polymer batteries
Dingguo Tang,Jianhong Liu,Lu Qi,Hui Chen,Yunxiang Ci
Chinese Science Bulletin , 2005, DOI: 10.1007/BF02897471
Abstract: Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) is one of the most popular polymers for polymer electrolyte membranes because of its excellent operating characteristics and superior electrochemical properties. The electrochemical performances of polymer electrolyte membrane can be enhanced by evenly dispersing nano-meter SiO2 particles in the polymer. In this paper, non-woven fabrics were immersed in the mixed solution of PVDF-HFP/ SiO2/butanone/butanol/plasticizer, and then dried in a vacuum oven to remove the solvents and the plasticizer and to make porous composite polymer electrolyte membranes. The prepared composite membranes supported by non-woven fabrics boast good mechanical strength and excellent electrochemical properties: the electrochemical stability window is 4.8 V vs. Li+/Li, and the ionic conductivity is 3.35×10 4 S/cm (around 60% of that of a common PE membrane) at room temperature. The lithium-ion polymer battery assembled by the composite membrane exhibits high rate capability and excellent cycling performance.
Composite polymer electrolyte membranes supported by non-woven fabrics for lithium-ion polymer batteries
Dingguo Tang,Jianhong Liu,Lu Qi,Hui Chen,Yunxiang Ci,
TANG Dingguo
,LIU Jianhong,QI Lu,CHEN Hui & CI Yunxiang . College of Chemistry and Molecular Engineering,Peking University,Beijing,China,. CITIC Guoan Mengguli Power Source Technology Co. Ltd.,Beijing,China

科学通报(英文版) , 2005,
Abstract: Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) is one of the most popular polymers for polymer electrolyte membranes because of its excellent operating characteristics and superior electrochemical properties. The electrochemical performances of polymer electrolyte membrane can be enhanced by evenly dispersing nano-meter SiO2 particles in the polymer. In this paper, non-woven fabrics were immersed in the mixed solution of PVDF-HFP/ SiO2/butanone/butanol/plasticizer, and then dried in a vacuum oven to remove the solvents and the plasticizer and to make porous composite polymer electrolyte membranes. The prepared composite membranes supported by non-woven fabrics boast good mechanical strength and excellent electrochemical properties: the electrochemical stability window is 4.8 V vs. Li+/Li, and the ionic conductivity is 3.35×10 4 S/cm (around 60% of that of a common PE membrane) at room temperature. The lithium-ion polymer battery assembled by the composite membrane exhibits high rate capability and excellent cycling performance.
Improved Cyclability of Liquid Electrolyte Lithium/Sulfur Batteries by Optimizing Electrolyte/Sulfur Ratio  [PDF]
Sheng S. Zhang
Energies , 2012, DOI: 10.3390/en5125190
Abstract: A liquid electrolyte lithium/sulfur (Li/S) cell is a liquid electrochemical system. In discharge, sulfur is first reduced to highly soluble Li 2S 8, which dissolves into the organic electrolyte and serves as the liquid cathode. In solution, lithium polysulfide (PS) undergoes a series of complicated disproportionations, whose chemical equilibriums vary with the PS concentration and affect the cell’s performance. Since the PS concentration relates to a certain electrolyte/sulfur (E/S) ratio, there is an optimized E/S ratio for the cyclability of each Li/S cell system. In this work, we study the optimized E/S ratio by measuring the cycling performance of Li/S cells, and propose an empirical method for determination of the optimized E/S ratio. By employing an electrolyte of 0.25 m LiSO 3CF 3-0.25 m LiNO 3 dissolved in a 1:1 (wt:wt) mixture of dimethyl ether (DME) and 1,3-dioxolane (DOL) in an optimized E/S ratio, we show that the Li/S cell with a cathode containing 72% sulfur and 2 mg cm ? 2 sulfur loading is able to retain a specific capacity of 780 mAh g ?1 after 100 cycles at 0.5 mA cm ?2 between 1.7 V and 2.8 V.
Membranes in Lithium Ion Batteries  [PDF]
Min Yang,Junbo Hou
Membranes , 2012, DOI: 10.3390/membranes2030367
Abstract: Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. The present review attempts to summarize the knowledge about some selected membranes in lithium ion batteries. Based on the type of electrolyte used, literature concerning ceramic-glass and polymer solid ion conductors, microporous filter type separators and polymer gel based membranes is reviewed.
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