Electrolyte Solvents For Batteries Research Articles

(Invited) Recent Progress in Understanding Battery Electrolyte Electrochemical Stability and Its Relationship with Electrolyte Structural Properties

Designing compatible electrochemical interfaces is paramount for enabling energy storage devices from batteries to electric double layer capacitors as electrolytes should be either electrochemically stable at the electrode and current collectors surfaces or form a stable electronically insulating but ionically conducting solid electrolyte interphase (SEI). Electrical double layer capacitors with narrow pores cannot rely on the SEI to extend their operating window placing more stringent requirements on electrolyte intrinsic electrochemical stability compared to batteries. In this presentation I will discuss a molecular scale insight into the initial mechanisms of battery electrolyte electrochemical degradation on the active and non-active electrodes obtained from a coordinated density functional theory (DFT) study and non-reactive molecular dynamics (MD) simulations of bulk and interfacial properties of electrolytes and the relationship between them. In the first part of the presentation, I will focus on understanding of electrolyte oxidation reactions on active and non-active electrodes. While HOMO screening for redox shuttle molecules was previously successful for quantitatively predicting trends, such screening is often not sufficient for traditional battery electrolyte solvents including cycling and linear carbonates, phosphates and sulfones.(1) Instead, quantum chemistry calculations have shown that the majority of battery solvents with the exception of the solvents with unsaturated functionalities such C=C double bonds do not undergo direct oxidation within typical operating range, instead their oxidation is coupled with the H-transfer to another solvent or oxygen of the electrode surface. Analogously, on the anode the F-transfer and LiF formation during anion and semi-fluorinated solvent reduction occurs at higher potentials compared to direct reduction of isolated anions and solvents.(2) Local ion and solvent environment influences both oxidation and reduction stability and initial decomposition reactions of electrolytes making electrolyte electrochemical stability dependent on the salt concentration and ion and solvent partitioning with the double layer that is in turn is dependent on the applied potential. Highly concentrated aqueous and non-aqueous electrolytes were found in MD simulations to exclude the solvent molecules from directly interacting with the positive electrode surface providing an additional mechanism for extending the electrolyte oxidation stability in addition to the widely discussed elimination of the “free” solvent from the electrolytes by increasing salt concentration.(3) In this presentation, I will give multiple examples on how changes in the double layer partitioning could be beneficial or detrimental to improving the electrode – electrolyte compatibility with aqueous and non-aqueous electrolytes. (4) References Borodin, O.; Olguin, M.; Spear, C. E.; Leiter, K.; Knap, J., Towards High Throughput Screening of Electrochemical Stability of Battery Electrolytes. Nanotechnology 2015, 26, 354003.Borodin, O.; Olguin, M.; Spear, C.; Leiter, K.; Knap, J.; Yushin, G.; Childs, A.; Xu, K., Challenges with Quantum Chemistry-Based Screening of Electrochemical Stability of Lithium Battery Electrolytes. ECS Transactions 2015, 69, 113-123.Vatamanu, J.; Borodin, O., Ramifications of Water-in-Salt Interfacial Structure at Charged Electrodes for Electrolyte Electrochemical Stability. J. Phys. Chem. Lett. 2017, 8, 4362-4367.Borodin, O. ; Ren, X.; Vatamanu, J.; Cresce, A. von Wald; Knap, J.; Xu, K. "A Modeling Insight into Battery Electrolyte Electrochemical Stability and Interfacial Structure" Acc. Chem. Res. 2017 (ASAP)

X-ray Raman spectroscopy of lithium-ion battery electrolyte solutions in a flow cell.

The effects of varying LiPF6 salt concentration and the presence of lithium bis(oxalate)borate additive on the electronic structure of commonly used lithium-ion battery electrolyte solvents (ethylene carbonate-dimethyl carbonate and propylene carbonate) have been investigated. X-ray Raman scattering spectroscopy (a non-resonant inelastic X-ray scattering method) was utilized together with a closed-circle flow cell. Carbon and oxygen K-edges provide characteristic information on the electronic structure of the electrolyte solutions, which are sensitive to local chemistry. Higher Li+ ion concentration in the solvent manifests itself as a blue-shift of both the π* feature in the carbon edge and the carbonyl π* feature in the oxygen edge. While these oxygen K-edge results agree with previous soft X-ray absorption studies on LiBF4 salt concentration in propylene carbonate, carbon K-edge spectra reveal a shift in energy, which can be explained with differing ionic conductivities of the electrolyte solutions.

Electrolyte solvents for high voltage lithium ion batteries: ion correlation and specific anion effects in adiponitrile.

We studied dynamic and structural properties of two lithium conducting salts in the aprotic organic solvent adiponitrile by a combination of atomistic molecular dynamics (MD) simulations, quantum chemical calculations, and experimental findings. The outcomes of our simulations reveal significant differences between both lithium salts, namely lithium tetrafluoroborate (LiBF4) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) at various concentrations, which can be mainly attributed to the solvation behavior of the individual anions. The increased tendency of ion complex formation for LiBF4 is reflected by lower values regarding the measured and computed effective ionic conductivities when compared to LiTFSI. All findings highlight the crucial importance of specific anion effects in combination with molecular details of solvation, and advocate the use of adiponitrile as a beneficial solvent in modern lithium ion battery technology with high voltage electrodes.

Effect of Using Fluorinated Ether and Sulfone as Electrolyte Solvents for Lithium Ion Batteries with Lithium-Rich Layered Cathodes and Silicon Oxide Anodes

We examined fluorinated ether and sulfone as electrolyte solvents for Lithium (Li) ion batteries with Li-rich layered cathodes and Silicon oxide anodes. We evaluated the mixture of cyclic carbonate, sulfone compound, and 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropopyl ether (FE1). The gas volume after the initial charge-discharge process increased with the amount of ethylene carbonate (EC) or 4-fluoro 1,3-dioxolane 2-one (FEC). These results show that the reaction between EC or FEC and cathode-active material can be considered to be the cause of gas evolution in the initial charge-discharge cycle. We evaluated sulfone compounds and low-viscosity solvents. By using electrolyte solution with ethyl isopropyl sulfone, FE1, and FEC as electrolyte solvents, the retention capacity after 500 cycles increased to around 67%, which was larger than that of conventional electrolyte solutions such as 1 M LiPF6 EC/diethyl carbonate (30/70 v/v).

Effect of Using Fluorinated Ether and Sulfone As Electrolyte Solvents for Lithium Ion Batteries with Lithium Rich Layered Cathode and Silicon Oxide Anode

Introduction Li rich layered cathode is one of the candidates for next generation cathode active material of Lithium ion batteries, because of large capacity more than 250 mAh/g. On the other hand, because of the higher potential than conventional cathode active materials, Li rich layered cathode has the problem of the capacity fading and gas emission. We have studied fluorinated electrolyte solvents for high voltage operation batteries with LiNi0.5Mn1.5O4 cathode1) 2), and we have reported that fluorinated ether and fluorinated phosphate were effective to reduce gas emission in high voltage operation cells at elevated temperature. In this report, we examined fluorinated ether and sulfone as electrolyte solvents for Lithium ion batteries with Li rich layered cathode and SiO anode. Experimental Li(LixNiyMn1-x-y)O2 was used as a cathode active material, and SiO was used as an active anode material. The discharge capacity as a function of cycle number was tested using stack type laminated cells with these active materials. Ethylene carbonate (EC), diethyl carbonate (DEC), DES (Diethyl sulfone) and 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (FE) were used as electrolyte solvents. EC/DEC (30/70 v/v) and EC/DES/FE (x/(30-x)/70 v/v/v (x=0,5,10)) were used as electrolyte solutions. The volume of the cells was measured by the Archimedes method before and after initial 3 charge discharge cycles between 4.5 V and 1.5 V. After that, cycle tests were performed between 4.5 V and 1.5 V at 45 ºC. Results Figure 1 shows discharge capacity retention as a function of cycle number for Li(LixNiyMn1-x-y)O2/SiO cells with electrolyte solutions of EC/DEC (30/70 v/v) and EC/DES/FE (5/25/70 v/v/v). Capacity retention of EC/DES/FE after 200 cycles was larger than that of EC/DEC. DES and FE seem to have higher oxidation resistance than DEC and to have the effect of cycle life improvement. Figure 2 shows the volumes increase of cells after initial 3 charge-discharge cycles at 45 °C. The cause of volume increase is gas emission. The volume increase of the cell with EC/DEC (30/70 v/v) was larger than that with EC/DES/FE (x/(30-x)/50 v/v/v). Gas volume increased with amount of EC in electrolyte of EC/DES/FE. This result shows that the cause of gas emission at initial charge-discharge process seems to be due to the reaction between electrolyte solvents and cathode. EC is considered to be the cause of gas emission in initial charge discharge cycles. References T.Noguchi, M.Uehara, Y.Katoh, K.Utsugi, PRiMe 2012 , No.824 (2012) T.Noguchi, Y.Katoh, K.Utsugi, 228th ECS Meeting , No.358(2015) Figure 1

An automated system for performing continuous viscosity versus temperature measurements of fluids using an Ostwald viscometer

An automated system was developed to measure the viscosity of fluids as a function of temperature using image analysis tracking software. An Ostwald viscometer was placed in a three-wall dewar in which ethylene glycol was circulated using a thermal bath. The system collected continuous measurements during both heating and cooling cycles exhibiting no hysteresis. The use of video tracking analysis software greatly reduced the measurement errors associated with measuring the time required for the meniscus to pass through the markings on the viscometer. The stability of the system was assessed by performing 38 consecutive measurements of water at 42.50 ± 0.05 °C giving an average flow time of 87.7 ± 0.3 s. A device was also implemented to repeatedly deliver a constant volume of liquid of 11.00 ± 0.03 ml leading to an average error in the viscosity of 0.04%. As an application, the system was used to measure the viscosity of two Li-ion battery electrolyte solvents from approximately 10 to 40 °C with results showing excellent agreement with viscosity values calculated using Gering's Advanced Electrolyte Model (AEM).

Benchmarking of computational approaches for fast screening of lithium ion battery electrolyte solvents

Electrolyte solvents play an important role in lithium-ion batteries. Hence, investigation of the solvent is key to improving battery functionality. We performed benchmark calculations to suggest the best conditions for rapid screening of electrolyte candidates using semi-empirical (SEM) calculations and density functional theory (DFT). A wide selection of Hamiltonians, DFT levels, and basis sets were used for this benchmarking with typical electrolyte solvents. The most efficient condition for reducing computational costs and time is VWN/DNP+ for DFT levels and PM3 for SEM Hamiltonians.

Fluorosilane compounds with oligo(ethylene oxide) substituent as safe electrolyte solvents for high-voltage lithium-ion batteries

Two fluorosilanes with oligo(ethylene oxide) unites were synthesized through hydrosilylation of chlorosilane with allyl substituted oligo(ethylene oxide) ether followed by fluorination with potassium fluoride. The synthesized fluorosilane compounds exhibited lower viscosity, higher dielectric constant and higher oxidation potential, compared with their non-fluorination counterparts. Difluoro(3-(2-(2-methoxyethoxy)ethoxy)propyl)methylsilane (DFSM2), one of the two compounds, was evaluated as high-voltage and thermal stable electrolyte co-solvent with the conventional carbonate-based electrolytes. Using an optimized electrolyte of 1M LiPF6 in EC/DFSM2/EMC (2/3/5 in vol.) with addition of 5 wt% fluoroethylene carbonate (FEC), high-voltage LiCoO2(LCO)/graphite full cell displayed outstanding cycling stability of 92.5% capacity retention after 135 cycles at 4.4 V upper cutoff voltage. Characterized by differential scanning calorimetry (DSC) analysis, the DFSM2-based electrolyte demonstrated higher thermal stability with lithiated graphite anode and delithiated LCO cathode, thus better safety feature compared with the conventional electrolyte.

Analysis on Extraction Behaviour of Lithium-ion Battery Electrolyte Solvents in Supercritical CO2by Gas Chromatography

Analysis on Extraction Behaviour of Lithium-ion Battery Electrolyte Solvents in Supercritical CO2by Gas Chromatography

Defective Graphene and Graphene Allotropes as High-Capacity Anode Materials for Mg Ion Batteries

Although rechargeable Mg ion batteries have recently received renewed interest as a promising alternative to Li ion batteries, the Mg metal used for anodes in state-of-the-art Mg ion batteries is not compatible with conventional battery electrolyte solvents. On the other hand, graphite electrode materials function well with common battery electrolyte solvents, but Mg intercalation into graphite is very difficult. In the case of two-dimensional (2D) carbon-based materials, pristine graphene, the most well-studied 2D material, is known to have no capacity for Li or Mg. Here we demonstrate the potential of defective 2D carbon-based structures to be used as high-capacity anode materials for Mg ion batteries. Adsorption of divalent Mg ions on defective graphene and graphene allotropes is predicted by first-principles density functional theory. Our results show enhanced Mg adsorption on both defective graphene and graphene allotropes. Moreover, we show that Mg storage capacity can be improved by increasing the ...

Hindered Glymes for Graphite-Compatible Electrolytes.

Organic carbonate mixtures are used almost exclusively as lithium battery electrolyte solvents. The linear compounds (dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate) act mainly as thinner for the more viscous and high-melting ethylene carbonate but are the least stable component and have low flash points; these are serious handicaps for lifetime and safety. Polyethers (glymes) are useful co-solvents, but all formerly known representatives solvate Li(+) strongly enough to co-intercalate in the graphite negative electrode and exfoliate it. We have put forward a new electrolyte composition comprising a polyether to which a bulky tert-butyl group is attached ("hindered glyme"), thus completely preventing co-intercalation while maintaining good conductivity. This alkyl-carbonate-free electrolyte shows remarkable cycle efficiency of the graphite electrode, not only at room temperature, but also at 50 and 70 °C in the presence of lithium bis(fluorosulfonimide). The two-ethylene-bridge hindered glyme has a high boiling point and a flash point of 80 °C, a considerable advantage for safety.

Effect of Using Fluorinated Phosphate Ester and Fluorinated Ether As Electrolyte Solvents for Lithium Ion Batteries with LiNi0.5Mn1.5-XTixO4 Cathode

Introduction LiNi0.5Mn1.5O4 1) is one of the candidates for next generation cathode active material of Li ion batteries, because of large capacity of around 130 mAh/g and the high charge-discharge potential of around 4.65V versus Li. On the other hand, because of the higher potential than conventional cathode active materials, 5V class spinel has the problem of the capacity fading due to decomposition of electrolyte and Mn dissolution. We have studied the improvement of lifetime by Ti substitution for Mn of LiNi0.5Mn1.5O4 2) 3) 4) 5). To suppress electrolyte decomposition, it was necessary to develop electrolyte solvents which have higher resistance to oxidation. The decomposition reaction of electrolyte may cause gas generation, and it can cause swelling of cells. At room temperature, amount of gas was not large even in conventional electrolyte, but in the case of operation at elevated temperature large amount of gas generation was a problem. We have reported the decrease of gas emission by using fluorinated phosphate (FPE) as an electrolyte solvent6). In this report, we evaluated the composition dependence of electrolytes with ethylene carbonate, FPE and fluorinated ether (FE). By results of HOMO value calculation, FE was expected to have higher resistance to oxidation than conventional solvents. Experimental LiNi0.5Mn1.5-xTixO4 was used as the cathode active material, and graphite was used as the active anode material. The discharge capacity as a function of cycle number was tested using stack type laminated cells with these active materials. 1 M solution of LiPF6 in 40:60(v/v) mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) or 0.8 M solution of LiPF6in 20:(80-x):x (v/v) (x = 0 to 50) mixture of EC, FPE and FE were used as electrolytes. Cycle tests were performed at 45 ºC. The volume of the cells was measured by the Archimedes method. Results Figure 1 shows discharge capacity retention as a function of cycle number for LiNi0.5Mn1.5-xTixO4/graphite cells with 0.8M-LiPF6EC/FPE/FE=20/(80-x)/x (v/v) (x=0,10,20,30, 50) as electrolytes. Capacity retention after charge-discharge cycles increased with FE content in electrolyte. By evaluating impedance tests, the increase of resistance after cycles was suppressed with increase of FE content. Existence of FE is thought to have the effect of suppress of forming SEI during charge-discharge cycles. Figure 2 shows the increase rate of cell volumes after 300 charge-discharge cycles at 45 °C. The volume increase ratio of the cell with EC/DMC=40/60 was 59%, and those of EC/FPE/FE=20/80/0 and EC/FPE/FE=20/50/30 were less than 1%. Amount of gas generation was found to be significantly reduced by using EC/FPE/FE. These results show that FE also had high oxidation resistance around 4.7V versus Li. References Qiming Zhong, Arman Bonakdarpour, Meijie Zhang, Yuan Gao, and J.R.Dahn, J.Electrochem.Soc., 144, 205, January 1997T.Noguchi, I.Yamazaki, T.Numata, M.ShirakataThe 44th Battery Symposium in Japan,2C12(2003)J.-H. Kim, S.-T. Myung, C. S. Yoon, I.-H. Oh, and Y.-K. Suna, J.Electrochem.Soc., 151, A1911 (2004)T.Noguchi, I.Yamazaki, T.Numata, M.Shirakata The 45th Battery Symposium in Japan,1B29(2004)T.Noguchi, I.Yamazaki, T.Numata, K.Utsugi #1378, 220th ECS MeetingT.Noguchi, M.Uehara, Y.Katoh, K.Utsugi #824, PRiMe 2012 Figure 1

Analysis of the Deterioration Mechanism of Si Electrode as a Li-Ion Battery Anode Using Raman Microspectroscopy

Propylene carbonate (PC) and an ionic liquid consisting of 1-[(2-methoxyethoxy)methyl]-1-methylpiperidinium (PP1MEM) and bis(trifluoromethanesulfonyl)amide (TFSA) were used as electrolyte solvents for Li-ion batteries, and the anode properties of Si electrodes were investigated using a thick film prepared by gas deposition without any binder or conductive additive. The Si electrode in PP1MEM-TFSA exhibited good cycle performance with a reversible capacity of 1050 mA h g–1 even at the 100th cycle, whereas the Si electrode in PC showed a capacity of only 110 mA h g–1. It is noteworthy that the electrode performance was significantly enhanced just by changing the electrolyte solvent to an ionic liquid even with the same Si used as the active material. Raman mapping analyses of the Si anodes after cycling were conducted to clarify the deterioration mechanisms of the electrodes. It was revealed that, in the case of PC, crystalline Si locally remained in the electrode after cycling, and Li–Si alloying and deall...

Large-scale virtual high-throughput screening for the identification of new battery electrolyte solvents: computing infrastructure and collective properties.

A volunteer computing approach is presented for the purpose of screening a large number of molecular structures with respect to their suitability as new battery electrolyte solvents. Collective properties like melting, boiling and flash points are evaluated using COSMOtherm and quantitative structure-property relationship (QSPR) based methods, while electronic structure theory methods are used for the computation of electrochemical stability window estimators. Two application examples are presented: first, the results of a previous large-scale screening test (PCCP, 2014, 16, 7919) are re-evaluated with respect to the mentioned collective properties. As a second application example, all reasonable nitrile solvents up to 12 heavy atoms are generated and used to illustrate a suitable filter protocol for picking Pareto-optimal candidates.

Fluorinated Electrolytes for 5-V Li-Ion Chemistry: Probing Voltage Stability of Electrolytes with Electrochemical Floating Test

A series of electrolyte formulations containing fluorinated cyclic carbonates and fluorinated linear carbonates with LiPF6 has been evaluated as electrolyte solvents for high-voltage Li-ion batteries. The anodic stability of the new electrolytes on fully charged spinel LiNi0.5Mn1.5O4 (LNMO) cathode was examined by electrochemical floating tests. The effects of fluorine substitution on the cyclic and linear carbonate, ratio of cyclic vs. linear carbonate, and LiPF6 concentration on the electrolyte oxidation stability were investigated. Based on this study, the floating test proved to be an effective tool for identification of stable electrolyte materials.

Charting the known chemical space for non-aqueous lithium-air battery electrolyte solvents.

Li-air batteries are very promising candidates for powering future mobility, but finding a suitable electrolyte solvent for this technology turned out to be a major problem. We present a systematic computational investigation of the known chemical space for possible Li-air electrolyte solvents. It is shown that the problem of finding better Li-air electrolyte solvents is not only - as previously suggested - about maximizing Li(+) and O2(-) solubilities, but also about finding the optimal balance of these solubilities with the viscosity of the solvent. As our results also show that trial-and-error experiments on known chemicals are unlikely to succeed, full chemical sub-spaces for the most promising compound classes are investigated, and suggestions are made for further experiments. The proposed screening approach is transferable and robust and can readily be applied to optimize electrolytes for other electrochemical devices. It goes beyond the current state-of-the-art both in width (considering the number of compounds screened and the way they are selected), as well as depth (considering the number and complexity of properties included).

Large-scale virtual high-throughput screening for the identification of new battery electrolyte solvents: evaluation of electronic structure theory methods

The performance of semi-empirical quantum mechanical (SQM), density functional theory (DFT) and wave function theory (WFT) methods is evaluated for the purpose of screening a large number of molecular structures with respect to their electrochemical stability to identify new battery electrolyte solvents. Starting from 100,000 database entries and based on more than 46,000 DFT calculations, 83 candidate molecules are identified and then used for benchmarking lower-level computational models (SQM, DFT) with respect to higher-level WFT reference data. A combination of SQM and WFT methods is suggested as a screening strategy at the electronic structure theory level. Using a subset of over 11,000 typical organic molecules and based on over 22,000 high-level WFT calculations, several simple models are tested for the prediction of ionization potentials (IPs) and electron affinities (EAs). Reference data are made available for the development of more sophisticated QSPR models.

Evaluation of Electrolyte Salts and Solvents for Na-Ion Batteries in Symmetric Cells

The cycle life of NaCrO2 in NaPF6 and NaTFSI in PC and EC/DEC (1/2 v/v) electrolytes were studied in half-cells and symmetric cells. Half-cells were found to be not useful for evaluating the cycling performance due to impedance growth at the Na foil electrode. Symmetric cells containing no Na foil were found to be more useful when used for cycling performance evaluation instead of half-cells. NaCrO2 in 1M NaTFSI in PC and NaPF6 in EC/DEC electrolytes performed well in symmetric cells, having coulombic efficiencies of 99.94% and greater. We believe that these are the highest coulombic efficiencies reported for Na-ion battery materials. In contrast, half-cell performance did not reflect the cycling performance of NaCrO2 and had no correlation to the symmetric cell performance. This illustrates the importance of symmetric cells for the evaluation of Na-ion battery materials. In addition to these findings, it was found that 1M NaTFSI salt solutions caused significant corrosion of the Al current collector, which could be suppressed by additions of NaPF6.

A New Look at the Stability of Dimethyl Sulfoxide and Acetonitrile in Li-O2 Batteries

Dimethyl sulfoxide (DMSO) and acetonitrile (MeCN) have recently been highlighted as promising electrolyte solvents for Li-O2 batteries. Possible reactions between these two solvents and Li2O2 are here discussed using X-ray photoelectron spectroscopy to analyze surface of the Li2O2 powder after direct contact with the solvents for different times of exposure. The results indicated that Li2O2 decomposes DMSO solvents, whereas no indication of degradation of MeCN by Li2O2 was observed.

Oxidative Stability and Initial Decomposition Reactions of Carbonate, Sulfone, and Alkyl Phosphate-Based Electrolytes

The oxidative stability and initial oxidation-induced decomposition reactions of common electrolyte solvents for batteries and electrical double layer capacitors were investigated using quantum chemistry (QC) calculations. The investigated electrolytes consisted of linear (DMC, EMC) and cyclic carbonate (EC, PC, VC), sulfone (TMS), sulfonate, and alkyl phosphate solvents paired with BF4–, PF6–, bis(fluorosulfonyl)imide (FSI–), difluoro-(oxalato)borate (DFOB–), dicyanotriazolate (DCTA–), and B(CN)4– anions. Most QC calculations were performed using the M05-2X, LC-ωPBE density functional and compared with the G4MP2 results where feasible. The calculated oxidation potentials were compared with previous and new experimental data. The intrinsic oxidation potential of most solvent molecules was found to be higher than experimental values for electrolytes even after the solvation contribution was included in the QC calculations via a polarized continuum model. The presence of BF4–, PF6–, B(CN)4–, and FSI– anions near the solvents was found to significantly decrease the oxidative stability of many solvents due to the spontaneous or low barrier (for FSI–) H- and F-abstraction reaction that followed the initial electron removal step. Such spontaneous H-abstraction reactions were not observed for the solvent complexes with DCTA– or DFOB– anions or for VC/anion, TMP/PF6– complexes. Spontaneous H-transfer reactions were also found for dimers of the oxidized carbonates (EC, DMC), alkyl phosphates (TMP), while low barrier H-transfer was found for dimers of sulfones (TMS and EMS). These reactions resulted in a significant decrease of the dimer oxidation potential compared to the oxidation potential of the isolated solvent molecules. The presence of anions or an explicitly included solvent molecule next to the oxidized solvent molecules also reduced the barriers for the oxidation-induced decomposition reaction and often changed the decomposition products. When a Li+ cation polarized the solvent in the ECn/LiBF4 and ECn/LiPF6 complexes, the complex oxidation potential was 0.3–0.6 eV higher than the oxidation potential of ECn/BF4– and ECn/PF6–.