Analgesic Use in Sports.

BACKGROUND: Consumption of medication to alleviate pain is widespread in Germany. Around 1.9 million men and women take analgesics every day; some 1.6 million persons are addicted to painkillers. Analgesic use is thought also to be common in sports, even in the absence of pain. The aim of this study was to assess the extent of painkiller use among athletes. METHODS: In line with the PRISMA criteria and the modified PICO(S) criteria, a systematic literature review was registered (Openscienceframework, https://doi. org/10.17605/OSF.IO/VQ94D) and carried out in PubMed and SURF. The publications identified (25 survey studies, 12 analyses of doping control forms, 18 reviews) were evaluated in standardized manner using the Newcastle Ottawa Scale (NOS) and AMSTAR (A MeaSurement Tool to Assess systematic Reviews). RESULTS: Analgesic use is widespread in elite sports. The prevalence varies between 2.8% (professional tennis) and 54.2% (professional soccer). Pain medication is also taken prophylactically in the absence of symptoms in some non-elite competitive sports. In the heterogeneous field of amateur sports the data are sparse and there is no reliable evidence of wide-reaching consumption of painkillers. Among endurance athletes, 2.1% of over 50 000 persons stated that they used analgesics at least once each month in connection with sports. CONCLUSION: Analgesic use has become a problem in many areas of professional/ competitive sports, while the consumption of pain medication apparently remains rare in amateur sports. In view of the increasing harmful use of or even addiction to painkillers in society as a whole, there is a need for better education and, above all, restrictions on advertising.

A volumetric and intra-diffusion study of solutions of AlCl3 in two ionic liquids - [C2TMEDA][Tf2N] and [C4mpyr][Tf2N].

Intra-diffusion coefficients (DSi) have been measured for the ionic liquid constituent ions and aluminium-containing species in aluminium chloride (AlCl3) solutions in the ionic liquids 1-(2-dimethyl-aminoethyl)-dimethylethylammonium bis(trifluoromethylsulfonyl)amide ([C2TMEDA][Tf2N]) and N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([C4mpyr][Tf2N]), to investigate whether spectroscopically detected interactions between the ions and AlCl3 affect these properties. Such electrolyte solutions are of interest for the electrowinning of aluminium. The temperature, composition and molar volume dependences are investigated. Apparent (Vϕ,1) and partial molar (V1) volumes for AlCl3 have been calculated from solution densities. For [C2TMEDA][Tf2N] solutions, Vϕ,1 increases with increasing solute concentration; for [C4mpyr][Tf2N] solutions, it decreases. In pure [C2TMEDA][Tf2N], the cation diffuses more quickly than the anion, but this changes as the AlCl3 concentration increases. In the [C4mpyr][Tf2N] solutions, the intra-diffusion coefficient ratio remains equal to that for the pure ionic liquid and the aluminium species diffuses at approximately the same rate as the anion at each composition. The intra-diffusion coefficients can be fitted to the Ertl-Dullien free volume power law by superposing the iso-concentration curves with concentration dependent, but temperature independent, molar volume offsets. This suggests that they are primarily dependent on the molar volume and secondarily on a colligative thermodynamic factor due to dilution by AlCl3. AlCl3 complexation by [Tf2N]- and [C2TMEDA]+, confirmed by 27Al, 15N and 19F NMR spectroscopy, seems to play a minor role. Our results indicate that the application of free volume theories might be fruitful in the study of the transport properties of ionic liquid solutions and mixtures.

Fluorinated Boron-Based Anions for Higher Voltage Li Metal Battery Electrolytes.

Lithium metal batteries (LMBs) require an electrolyte with high ionic conductivity as well as high thermal and electrochemical stability that can maintain a stable solid electrolyte interphase (SEI) layer on the lithium metal anode surface. The borate anions tetrakis(trifluoromethyl)borate ([B(CF3)4]-), pentafluoroethyltrifluoroborate ([(C2F5)BF3]-), and pentafluoroethyldifluorocyanoborate ([(C2F5)BF2(CN)]-) have shown excellent physicochemical properties and electrochemical stability windows; however, the suitability of these anions as high-voltage LMB electrolytes components that can stabilise the Li anode is yet to be determined. In this work, density functional theory calculations show high reductive stability limits and low anion-cation interaction strengths for Li[B(CF3)4], Li[(C2F5)BF3], and Li[(C2F5)BF2(CN)] that surpass popular sulfonamide salts. Specifically, Li[B(CF3)4] has a calculated oxidative stability limit of 7.12 V vs. Li+/Li0 which is significantly higher than the other borate and sulfonamide salts (≤6.41 V vs. Li+/Li0). Using ab initio molecular dynamics simulations, this study is the first to show that these borate anions can form an advantageous LiF-rich SEI layer on the Li anode at room (298 K) and elevated (358 K) temperatures. The interaction of the borate anions, particularly [B(CF3)4]-, with the Li+ and Li anode, suggests they are suitable inclusions in high-voltage LMB electrolytes that can stabilise the Li anode surface and provide enhanced ionic conductivity.

Spectroscopic and Computational Study of Boronium Ionic Liquids and Electrolytes.

Boronium cation-based ionic liquids (ILs) have demonstrated high thermal stability and a >5.8 V electrochemical stability window. Additionally, IL-based electrolytes containing the salt LiTFSI have shown stable cycling against the Li metal anode, the "Holy grail" of rechargeable lithium batteries. However, the basic spectroscopic characterisation needed for further development and effective application is missing for these promising ILs and electrolytes. In this work, attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and density functional theory (DFT) calculations are used in combination to characterise four ILs and electrolytes based on the [NNBH2 ]+ and [(TMEDA)BH2 ]+ boronium cations and the [FSI]- and [TFSI]- anions. By using this combined experimental and computational approach, proper understanding of the role of different ion-ion interactions for the Li cation coordination environment in the electrolytes was achieved. Furthermore, the calculated vibrational frequencies assisted in the proper mode assignments for the ILs and in providing insights into the spectroscopic features expected at the interface created when they are adsorbed on a Li(001) surface. A reproducible synthesis procedure for [(TMEDA)BH2 ]+ is also reported. The fundamental findings presented in this work are beneficial for any future studies that utilise IL based electrolytes in next generation Li metal batteries.

A Hybrid Anion for Ionic Liquid and Battery Electrolyte Applications: Half Triflamide, Half Carbonate.

The synthesis of a new imide type anion, methylcarbonate(trifluoromethylsulfonyl)imide (MCTFSI) is described and the physicochemical properties of its sodium and N-butyl-N-methyl pyrrolidinium salts as well as structural information obtained by X-ray diffraction studies of the sodium salt are discussed in terms of charge delocalisation, coordination chemistry and electrochemical behaviour with respect to the analogous imdides bis(trifluoromethanesulfonyl)imide (TFSI) and bis(fluorosulfonyl)imide (FSI). The insight obtained from studying the new anion informs and reemphasizes the concept of weakly coordinating anions and coordination chemistry in designing electrolyte salts.

Tetracarboxylate Bis-Bipyridine Ruthenium Dyes: Synthesis, Structural and Electronic Characterisation.

The preparation of ruthenium complexes with novel 2,2'-bipyridine (bpy) ligands bearing four carboxylic acid groups was investigated with a view to creating dyes containing more than two potential anchoring groups per bpy unit for attachment to a titania surface. Synthetic challenges are encountered upon using the 2,2'-bipyridine-3,3',4,4'-tetracarboxylic acid ligand because it readily decarboxylates. The use of the methyl esterified derivative (3) proved to be more successful for complex preparation, with a robust preparation of the [Ru(3)2 Cl2 ] complex identified with diglyme as the solvent. This complex was further converted into the thiocyanato complex, [Ru(3)2 (NCS)2 ], which could not be completely de-esterified. X-ray analysis of crystals obtained from a mixture of isomers for this complex provided data for the S,S- and N,S-coordinated isomers; both showed a twisted arrangement of the pyridine rings in the 2,2'-bipyridine-3,3',4,4'-tetracarboxylic acid ligand, owing to steric hinderance. Conversely, the isosteric 2,2'-bipyridine-4,4',5,5'-tetracarboxylic acid ligand was easily converted into the desired [Ru(2)2 (NCS)2 ] complex through a standard one-pot procedure in N,N-dimethylformamide solvent. All of the complexes presented herein exhibit a significant redshift for the metal to ligand charge-transfer bands, relative to the benchmark ruthenium dye N719 and derivatives thereof. All complexes exhibit a quasi-reversible process for the ruthenium(II/III) couple at approximately 0.4 V versus the ferrocene couple, comparable to analogous ruthenium dyes.

Strength Training for Women as a Vehicle for Health Promotion at Work.

BACKGROUND: Women, on average, have less muscle strength than men. This anthropometric-physiological trait may make them more vulnerable to ex - cessive physical strain, injury, and inability to work. Strength training is used for preventive health maintenance and to lessen musculoskeletal symptoms. In this context, we studied whether the degree of muscle strength has any effect on women's health in everyday working life, and also the effects of strength training for women on their health in the workplace. METHODS: We systematically searched the PubMed/MEDLINE, Embase, CINAHL, Web of Science, CENTRAL, and SPOLIT databases for pertinent publications, in accordance with the PRISMA criteria for literature searches. We analyzed all of the retrieved randomized controlled trials conducted on women aged 18 to 65 to determine the effects of training on muscle strength, physical performance ability, and health-related parameters including body composition, musculo - skeletal pain, and subjective well-being. RESULTS: We did not find any studies that provided answers to the first question. As for the second question, the selection criteria were met by 12 of the 4969 retrieved studies, which dealt with the effect of strength training on health in the occupational environment and involved a total of 1365 female subjects. These studies were carried out in heterogeneous subject groups, with a variety of overlapping interventions consisting of both strength and endurance training. Significantly increased strength was found in all studies, as was a reduction of pain in all of the studies where this question was asked. Inconsistent results were obtained with respect to body weight, body composition, and subjective well-being. CONCLUSION: The interventions that were conducted in these studies succeeded in increasing strength and reducing pain, even when the training was brief and of low intensity. This was true not only for women working in occupations requiring unusual physical strength, but also for those in sedentary occupations. The small number of studies performed on this subject to date is surprising in view of the high prevalence of musculoskeletal symptoms in women.

The importance of transport property studies for battery electrolytes: revisiting the transport properties of lithium-N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide mixtures.

Transport properties are examined in some detail for samples of the low temperature molten salt N-propyl-N-methyl pyrrolidinium bis(fluorosulfonyl)imide [Pyr13][FSI] from two different commercial suppliers. A similar set of data is presented for two different concentrations of binary lithium-[Pyr13][FSI] salt mixtures from one supplier. A new and significantly different production process is used for the synthesis of Li[FSI] as well as the [Pyr13]+ salt used in the mixtures. Results for the viscosity, conductivity, and self-diffusion coefficients, together with the density and expansivity and apparent molar volume, are reported over the temperature range of (0 to 80) °C. The data for neat [Pyr13][FSI] are discussed in the context of velocity cross correlation (VCC or fij) and Laity resistance (rij) coefficients. Unusually, f+- ∼ f++ < f--. The three resistance coefficients are of similar magnitude indicating all three ion-ion interactions contribute to the transport properties, not just the cation-anion interaction. The composition dependence of the transport properties is compared to previously reported data for the same and related compounds: in contrast to high-temperature molten salt mixtures, this is an exponential dependence. The Nernst-Einstein parameter Δ, which contains information on the correlations of the ionic velocities and is determined by differences in the VCC for the various ion-ion combinations, was calculated for both the neat ionic liquid and its binary mixture. It increases with increasing lithium concentration. The new data set also allows some conclusions with regards to the lithium-[FSI]- coordination environment.

Even One Is Too Much: Sole Presence of One of the Risk Factors Overweight, Lack of Exercise, and Smoking Reduces Physical Fitness of Young Soldiers.

Health and physical fitness are key factors for soldiers. Increased sedentary military work, significant sitting periods during commuting and leisure time, and unhealthy dietary habits have caused a considerable increase in the number of physically unfit soldiers. Even worse, the adoption of harmful lifestyle habits occurs increasingly earlier in life. The aim of this cross-sectional study was (a) to determine the physical fitness of young male soldiers and (b) to investigate the association between physical fitness and both the presence and frequency of the health risk factors overweight, smoking, and lack of exercise. A total of 4,553 volunteers aged 18-25 years performed the Basis Fitness Test consisting of the 3 disciplines agility (11 × 10 m shuttle sprint), strength (flexed-arm hang), and endurance (1,000-m run). The presence and frequency of risk factors were determined by means of anthropometric measures (body mass index, waist circumference) and questionnaire data. The portion of soldiers without risk factors decreased from 49.4% (18-year-olds) to 16.4% for 25-year-olds. Persons without risk factors completed the agility test in 41.1 ± 3.7 seconds, flexed-arm hang in 60.1 ± 19.7 seconds, and 1,000-m run in 235 ± 32 seconds. Physical performance in all dimensions tested (agility, strength, endurance) notably deteriorated with the sole presence of one of the risk factors overweight, smoking, and lack of exercise. Any further risk factor led to further fitness decreases (p < 0.001). Mean performances of soldiers with 3 risk factors were 46.7 ± 4.1 seconds (11 × 10 m shuttle sprint), 27.6 ± 6.4 seconds (flexed-arm hang), and 298 ± 45 seconds (1,000-m run). Impacts of unhealthy lifestyles and significant losses in physical fitness are already visible in young male soldiers. Armed Forces must intensify their efforts to maintain health and performance of their soldiers.

Concept for a Predeployment Assessment of Basic Military Fitness in the German Armed Forces.

Military fitness is defined as a hierarchical 4-level construct in the German armed forces: (a) "Fundamental/Baseline Fitness," (b) "Basic Military Fitness," (c) "Task Fitness," and (d) "Mission Fitness." "Fundamental/Baseline Fitness" is assessed with the "Basic Fitness Test." However, this test alone is not sufficient to assess readiness for the physical demands of deployments. The first part of the article describes the development of a tool mirroring the specific physiological requirements of military operations on a joint forces level. The "Basic Military Fitness Tool" (BMFT) combines 4 crucial military demands into one single timed test run performed with field uniform (5 kg), body armor (13.4 kg), and helmet (1.6 kg): (a) maneuver under fire: 130 m run with changes in direction, velocity, and body position, (b) casualty rescue: 40 m of dragging a 50 kg load, (c) load carrying: 100 m carrying of two 18 kg loads, and (d) load lifting: lifting a 24 kg load on to a 1.25 m high rack 5 times. The second part covers the first assessment of BMFT selectivity between high- and low-performing groups. Muscle mass and strength are important factors for working with loads. Thus, female soldiers are expected to need more time to complete BMFT because of their on average lower muscle mass. Eighteen female (age = 28.5 ± 6.6 years, lean body mass [LBM] = 45.0 ± 4.5 kg; mean ± SD) and 104 male soldiers (age = 30.0 ± 8.4, LBM = 64.3 ± 7.1) completed isometric strength testing (hand grip = 344.3 ± 51.4 N and 547.3 ± 79.1 N, elbow flexors = 118.9 ± 16.9 and 235.1 ± 42.0, knee extensors = 433.2 ± 87.4 and 631.4 ± 111.4) and BMFT (259.2 ± 44.0 and 150.0 ± 21.1 s). Except age, all variables differed significantly (p < 0.01) between groups.

Studies on the nuances of the electrochemically induced room temperature isomerization of cis-stilbene in acetonitrile and ionic liquids.

Electrochemical reduction of cis-stilbene occurs by two well-resolved one-electron reduction steps in acetonitrile with (n-Bu)4NPF6 as the supporting electrolyte and in N-butyl-N-methylpyrrolidinium (Pyrr1,4(+)) and (trimethylamine)(dimethylethylamine)-dihydroborate bis(trifluoromethylsulfonyl)amide (NTf2(-)) ionic liquids (ILs). Mechanistic details of the electroreduction have been probed by dc and Fourier transformed ac voltammetry, simulation of the voltammetry, bulk electrolysis, and EPR spectroscopy. The first one-electron reduction induces fast cis to trans isomerization in CH3CN and ILs, most likely occurring via disproportionation of cis-stilbene radical anions and fast transformation of the cis-dianion to the trans-configuration. The second reduction process is chemically irreversible in CH3CN due to protonation of the dianion but chemically reversible in highly aprotic ILs under high cis-stilbene concentration conditions. Increase of the (n-Bu)4NPF6 supporting electrolyte concentration (0.01-1.0 M) in CH3CN induces substantial positive shifts in the potentials for reduction of cis-stilbene, consistent with strong ion pairing of the anion radical and dianion with (n-Bu)4N(+). However, protection by ion pairing against protonation of the stilbene dianions or electrochemically induced cis-trans-stilbene isomerization is not achieved. Differences in electrode kinetics and reversible potentials for cis-stilbene(0/•-) and trans-stilbene(0/•-) processes are less pronounced in the Pyrr1,4-NTf2 ionic liquid than in the molecular solvent acetonitrile.

Transport, electrochemical and thermophysical properties of two N-donor-functionalised ionic liquids.

Two N-donor-functionalised ionic liquids (ILs), 1-ethyl-1,4-dimethylpiperazinium bis(trifluoromethylsulfonyl)amide (1) and 1-(2-dimethylaminoethyl)-dimethylethylammonium bis(trifluoromethylsulfonyl)amide (2), were synthesised and their electrochemical and transport properties measured. The data were compared with the benchmark system, N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (3). Marked differences in thermal and electrochemical stability were observed between the two tertiary-amine-functionalised salts and the non-functionalised benchmark. The former are up to 170 K and 2 V less stable than the structural counterpart lacking a tertiary amine function. The ion self-diffusion coefficients (Di ) and molar conductivities (Λ) are higher for the IL with an open-chain cation (2) than that with a cyclic cation (1), but less than that with a non-functionalised, heterocyclic cation (3). The viscosities (η) show the opposite behaviour. The Walden [Λ[proportionality](1/η)(t) ] and Stokes-Einstein [Di /T)[proportionality](1/η)(t) ] exponents, t, are very similar for the three salts, 0.93-0.98 (±0.05); that is, the self-diffusion coefficients and conductivity are set by η. The Di for 1 and 2 are the same, within experimental error, at the same viscosity, whereas Λ for 1 is approximately 13% higher than that of 2. The diffusion and molar conductivity data are consistent, with a slope of 0.98±0.05 for a plot of ln(ΛT) against ln(D+ +D- ). The Nernst-Einstein deviation parameters (Δ) are such that the mean of the two like-ion VCCs is greater than that of the unlike ions. The values of Δ are 0.31, 0.36 and 0.42 for 3, 1 and 2, respectively, as is typical for ILs, but there is some subtlety in the ion interactions given 2 has the largest value. The distinct diffusion coefficients (DDC) follow the order D(d)__ < D(d)++ < D(d)+_, as is common for [Tf2N](-) salts. The ion motions are not correlated as in an electrolyte solution: instead, there is greater anti-correlation between the velocities of a given anion and the overall ensemble of anions in comparison to those for the cationic analogue, the anti-correlation for the velocities of which is in turn greater than that for a given ion and the ensemble of oppositely charged ions, an observation that is due to the requirement for the conservation of momentum in the system. The DDC also show fractional SE behaviour with t~0.95.

The observation of dianions generated by electrochemical reduction of trans-stilbenes in ionic liquids at room temperature.

Three highly aprotic bis(trifluoromethylsulfonyl)amide (NTf2(-)) based ionic liquids (ILs) containing the cations trihexyl(tetradecyl)phosphonium (P6,6,6,14(+)), N-butyl-N-methylpyrrolidinium (Pyrr4,1(+)), and (trimethylamine)(dimethylethylammine)dihydroborate ((N111)(N112)BH2(+)) have been examined as media for room temperature voltammetric detection of highly basic stilbene dianions electrochemically generated by the reduction of trans-stilbene (t-Stb) and its derivatives (4-methoxy-, 2-methoxy-, 4,4'-dimethyl-, and 4-chloromethyl-). Transient and steady-state data in the ILs were compared with results obtained in the molecular solvent acetonitrile. In all media examined, the t-Stb(0/•-) process is chemically and electrochemically reversible with a heterogeneous charge transfer rate constant in CH3CN of 1.5 cm s(-1), as determined by Fourier transformed AC voltammetry. However, further reduction to the dianion was always irreversible in this molecular but weakly acidic solvent. On the other hand, a substantial level of chemical reversibility for the reduction of t-Stb(•-) to t-Stb(2-) on the time scale of cyclic voltammetry is achieved when the concentration of trans-stilbene, [t-Stb], appreciably exceeds the concentration of adventitious water or other proton sources. In particular, these conditions are met when [t-Stb] ≥ 0.1 M in thoroughly dehydrated and purified ILs, while in the presence of CH3CN, t-Stb(2-) still suffers fast irreversible protonation under these stilbene concentration conditions. The E0/•-(0) values (vs Fc(0/+)) for substituted trans-stilbenes in acetonitrile and (N111)(N112)BH2-NTf2 do not differ substantially, nor do the E0/•-(0) and E•-/2-(0) differences or other aspects of the voltammetric behavior.

The influence of thermal degradation on the electrodeposition of aluminium from an air- and water-stable ionic liquid.

Aluminium electrodeposition is demonstrated from a thermally degraded ionic liquid solution. NMR and voltammetric analyses established that Al(3+) reduction was remarkably similar to that in non-degraded IL solutions suggesting that the electroactive metal-containing species was unaffected by heat treatment. Electron microscopy revealed a significant grain refinement of the deposited metal.

Physical fitness, weight, smoking, and exercise patterns in young adults.

INTRODUCTION: The health and physical fitness of adolescents and young adults are important not just to the individuals concerned, but also to society as a whole. Many studies from many different countries have dealt with the prevalence of overweight, the risk factors for it, and the morbidity it causes, but no more than a few have addressed the effects of unhealthy lifestyles on physical fitness. In this study, we show that young adults' physical performance depends on the number of risk factors they possess. We also compare the young adults' physical performance with that of adolescents aged 10 to 17. METHODS: We obtained cross-sectional data on the weight, smoking status, athletic activity, time to run 1 km, and ability to perform a chin-up on a horizontal bar of 8048 subjects aged 10 to 25. The young adults were divided into groups depending on the number of risk factors they possessed from the following list: overweight, smoking, and lack of exercise. RESULTS: 28.4% of the men and 35.4% of the women aged 18 to 25 had none of these risk factors and exhibited the best physical performance. The more risk factors were present, the worse physical performance became. The 24- and 25-year-olds performed at the same level as the 14- and 15-year-olds. DISCUSSION: Unhealthy lifestyles can impair physical fitness even before any chronic disease arises. Possession of even a single risk factor is associated with significantly worse performance. Unless comprehensive and effective interventions are introduced in school and at work, the further cementation and worsening of unhealthy lifestyles will be hard to stop.

Importance of sports during youth and exercise barriers in 20- to 29-year-old male nonathletes differently motivated for regular physical activities.

The number of sedentary young adults has dramatically increased in past decades, and sedentary lifestyles are adopted at an increasingly earlier age. Little is known about barriers or predictors to (re)initiate regular physical activity in this group. The purpose of the study is to (a) identify subgroups in nonathletes differing in their amenability to physical exercise, (b) to analyze them for differences in barriers and intention to exercise, and (c) compare importance of sports during youth in nonathletes to trained peers. Using a health and fitness questionnaire 589 nonathletes were queried in the cross-sectional survey and compared with 270 trained peers. Athletic abstainers (A), lower (L), and higher (H) motivated nonathletes were separated based on previous engagement in sports. Of the nonathletes, 54.7% reported only 1 barrier to exercise. Although this feature was most prominent in H (71.5%), the other groups showed significantly more barriers and a broader distribution. Similar characteristics but minor differences were observed for perceived importance of sports during youth. The most significant differences between athletes and nonathletes emerged enquiring the attitude and activity of the parents. The majority of nonathletes (72.8%) indicate their intention to exercise in the future. Their intention differed significantly in H (88.1%), L (76.1%), and A (59.1%). However, there are good reasons to doubt that most of those intending nonathletes will actually become physically active. Even in the analyzed narrow age range of men different motivated groups of nonathletes were found. Because of the differences in receptiveness and approachability health promotion policies may not only consider the often recommended tailored interventions but also carefully designed incentive programs.

Realisation of an all solid state lithium battery using solid high temperature plastic crystal electrolytes exhibiting liquid like conductivity.

Replacement of volatile and combustible electrolytes in conventional lithium batteries is desirable for two reasons: safety concerns and increase in specific energy. In this work we consider the use of an ionic organic plastic crystal material (IOPC), N-ethyl-N-methylpyrrolidinium tetrafluoroborate, [C2mpyr][BF(4)], as a solid-state electrolyte for lithium battery applications. The effect of inclusion of 1 to 33 mol% lithium tetrafluoroborate, LiBF(4), into [C2mpyr][BF(4)] has been investigated over a wide temperature range by differential scanning calorimetry (DSC), impedance spectroscopy, cyclic voltammetry and cycling of full Li|LiFePO(4) batteries. The increases in ionic conductivity by orders of magnitude observed at higher temperature are most likely associated with an increase in Li ion mobility in the highest plastic phase. At concentrations >5 mol% LiBF(4) the ionic conductivity of these solid-state composites is comparable to the ionic conductivity of room temperature ionic liquids. Galvanostatic cycling of Li|Li symmetrical cells showed that the reversibility of the lithium metal redox reaction at the interface of this plastic crystal electrolyte is sufficient for lithium battery applications. For the first time we demonstrate an all solid state lithium battery incorporating solid electrolytes based on IOPC as opposed to conventional flammable organic solvents.

Comparison of diffusivity data derived from electrochemical and NMR investigations of the SeCN¯/(SeCN)2/(SeCN)3¯ system in ionic liquids.

Electrochemical studies in room temperature ionic liquids are often hampered by their relatively high viscosity. However, in some circumstances, fast exchange between participating electroactive species has provided beneficial enhancement of charge transport. The iodide (I¯)/iodine (I(2))/triiodide (I(3)¯) redox system that introduces exchange via the I¯ + I(2) ⇌ I(3)¯ process is a well documented example because it is used as a redox mediator in dye-sensitized solar cells. To provide enhanced understanding of ion movement in RTIL media, a combined electrochemical and NMR study of diffusion in the {SeCN¯-(SeCN)(2)-(SeCN)(3)¯} system has been undertaken in a selection of commonly used RTILs. In this system, each of the Se, C and N nuclei is NMR active. The electrochemical behavior of the pure ionic liquid, [C(4)mim][SeCN], which is synthesized and characterized here for the first time, also has been investigated. Voltammetric studies, which yield readily interpreted diffusion-limited responses under steady-state conditions by means of a Random Assembly of Microdisks (RAM) microelectrode array, have been used to measure electrochemically based diffusion coefficients, while self-diffusion coefficients were measured by pulsed field gradient NMR methods. The diffusivity data, derived from concentration and field gradients respectively, are in good agreement. The NMR data reveal that exchange processes occur between selenocyanate species, but the voltammetric data show the rates of exchange are too slow to enhance charge transfer. Thus, a comparison of the iodide and selenocyanate systems is somewhat paradoxical in that while the latter give RTILs of low viscosity, sluggish exchange kinetics prevent any significant enhancement of charge transfer through direct electron exchange. In contrast, faster exchange between iodide and its oxidation products leads to substantial electron exchange but this effect does not compensate sufficiently for mass transport limitations imposed by the higher viscosity of iodide RTILs.