Thianthrene-functionalized polynorbornenes were investigated as high-voltage organic cathode materials for dual-ion cells. The polymers show reversible oxidation reactions in solution and as a solid in composite electrodes. Constant current investigations displayed a capacity of up to 66 mA h g(-1) at a high potential of 4.1 V vs. Li/Li(+).

Solid electrolyte interphase (SEI) forming electrolyte additives are able to improve the performance of lithium ion and lithium metal batteries. In this work, the electrochemical performance of graphite and lithium metal, when using 1 M LiTFSI (lithium bis(trifluoro-methanesulfonyl)imide) in tetraethylene glycol dimethyl ether (TEGDME) with and without the addition of different amounts of fluoroethylene carbonate (FEC), is compared. It is shown that 1 M LiTFSI in TEGDME without additive is not able to form an effective SEI on graphite and that this electrolyte is also continuously decomposing on lithium metal. By the addition of > 2 wt% FEC, an effective SEI is formed on both, lithium metal and graphite, enabling good cycling stability. Furthermore, 1 M LiTFSI in TEGDME with FEC as additive is a suitable electrolyte for lithium iron phosphate (LFP) based lithium ion batteries.In analogy to metallic lithium and lithium-rich "lithium-alloys", lithiated (charged) graphite/carbon is thermodynamically unstable in the typically used organic solvent-based electrolytes. 1 Therefore, the carbon surfaces, which are exposed to the electrolyte, have to be kinetically protected by an solid electrolyte interphase (SEI). 2 Nevertheless, there are significant differences in the SEI formation process between metallic lithium and graphite/carbon. 3 Film formation on metallic lithium takes place right upon contact with the electrolyte. The various electrolyte components decompose spontaneously with low selectivity on the Li metal surface and parts of the decomposition products form the SEI. Due to an increase in IR drop across the SEI, with SEI growth, the reactivity of metallic lithium electrode vs. electrolyte decreases. As a consequence, the reduction of the electrolyte becomes more and more selective. The number of electrolyte components, which are still sensitive to reduction vs. the (now partially electronically "passivated") lithium electrode are limited. On the contrary, SEI formation on carbonaceous lithium storage materials takes place as a charge consuming side reaction in the first few cycles, especially during the first reduction (charge reaction). The electrolyte components, which are the least stable toward reduction, selectively react first. This makes SEI forming electrolyte additives particularly attractive for the use with carbonaceous anodes. When the electrolyte additive forms an effective SEI and is sensitive to reduction, the additive is reduced first and forms an initial SEI before reduction reactions of the other (main) electrolyte components takes place. 4 With the addition of suitable electrolyte additives, the initial SEI can be tailored and appropriate cell formation can be achieved. As a result of the different SEI formation processes, the SEI compositions on lithium metal and on carbonaceous anodes are different. 3,5 In addition to the above mentioned differences, the surface of metallic lithium is periodically renewed during cycling, causing formation of a new SEI in each following cycle (Figure 1). ...

Safety issues caused by the metallic lithium inside a battery represent one of the main reasons for the lack of commercial availability of rechargeable lithium‐metal batteries. The advantage of anodes based on coated lithium powder (CLiP), compared to plain lithium foil, include the suppression of dendrite formation, as the local current density during stripping/plating is reduced due to the higher surface area. Another performance and safety advantage of lithium powder is the precisely controlled mass loading of the lithium anode during electrode preparation, giving the opportunity to avoid Li excess in the cell. As an additional benefit, the coating makes electrode manufacturing safer and eases handling. Here, electrodes based on coated lithium powder electrodes (CLiP) are introduced for application in lithium‐metal batteries. These electrodes are compared to lithium foil electrodes with respect to cycling stability, coulombic efficiency of lithium stripping/plating, overpotential, and morphology changes during cycling.

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This essay explores Anthony Trollope’s decision to identify Phineas Finn, of his various “Palliser Novels,” as Irish. Many Victorian readers questioned Phineas’s ethnicity and lack of stereotypically Irish characteristics, and Trollope himself renounced this decision in his autobiography. The character’s Irishness, however, seems to be more than a gimm ick to differentiate the novel from similar tales of aspiring members of Parliament; in Phineas Finn, the author uses ethnicity to invert the national marriage trope. Trollope employs gendered ethnic stereotypes, casting his title character as feminine in his romantic entanglements and even his political behavior, while the English ladies he meets are described as masculine. But the character of Phineas emerges as more complicated than a feminine or emasculated one; in his tenuous loyalty to his docile Irish sweetheart, Phineas becomes a conventional male lead. His Irishness, then, lends a duality to his character that encompasses more than merely two national identities; it embodies two entirely different kinds of men: one masculine and the other feminine, one a philanderer and the other loyal, one English and the other Irish.

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Organic materials are well known as electrode-active materials in rechargeable batteries.[ 1 ] Since the early 80s, conductive polymers have been utilized as electrodes in energy storage devices while undergoing doping/undoping processes.[ 2 , 3 ] Additionally, the substitution of polymers with functional groups or specialized molecules (localized redox centers), so called redox polymers, has been investigated.[ 4 ] One of the most studied functionalized polymers is poly (2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA).[ 5 ] This TEMPO-radical-based poly­methacrylate network grants high rate capabilities, while providing a stable capacity of around 110 mAh g-1 with an oxidation potential of 3.6 V vs. Li/Li+.[ 6 , 7 ] Nevertheless, such redox polymer-based systems still suffer from low specific capacities (~ 120 mAh g-1) compared to commercially available cathode battery materials (e.g. LiCoO2: 140 mAh g-1).[ 1 , 8 ] In order to optimize the electrochemical performance of redox polymers in terms of power and energy density, we have been investigating substituents for polymeric backbones with high working potentials, focussing on thianthrene as redox-active functional group. The interest on thianthrene is related to the high redox potential range of 4.01 – 4.10 V vs. Li/Li+ and the ability to form stabilized radical cations during oxidation.[ 9 ] Free thianthrene molecules have already been investigated as an overcharge protection additive in Lithium-ion batteries, but not as redox-active cathode materials for dual-ion batteries.[ 10 , 11 ] The general working principle of a thianthrene-based dual-ion battery is shown Figure 1. During charging (oxidation of thianthrene), anions are inserted into the polymer structure and the cations are intercalated into graphite, a so called dual-ion insertion process.[ 11 ] In this work, the addition of thianthrene to a polymeric backbone and the study of the applicability as organic cathode material are presented. The resulting thianthrene-functionalized polymers exhibit oxidation potentials of above 4.10 V vs. Li/Li+ (Figure 2). This oxidation potential is, to the best of our knowledge, one of the highest published values for organic-based electrode materials.[ 1 , 3 ] The synthesis of three different thianthrene-functionalized polymers with a polynorbornene backbone via ring-opening metathesis polymerization (ROMP) technique as well as their characterization using NMR spectroscopy will be shown. In addition, electrochemical investigations, as cyclic voltammetry (CV) and constant current cycling (CCC), are performed. CV results exhibit stable oxidation and reduction potentials of the polymers in solution and also when used as composite electrode. We could achieve capacities (related to anion insertion) up to 66 mAh g-1 depending on the electrolyte formulation. Combined with the high redox potential of the synthesized materials, a promising new class of functionalized polymers for application as organic cathode materials in rechargeable batteries is proposed. [1]       Liang, Y.; Tao, Z.; Chen, J., Adv. Energy Mater. 2012, 2 (7), 742-769. [2]       Armand, M., J. Phys. Colloques 1983, 44 (C3), C3-551-C3-557. [3]       Novák, P.; Müller, K.; Santhanam, K. S. V.; Haas, O., Chem. Rev. 1997, 97 (1), 207-282. [4]       Kaufman, F. B.; Schroeder, A. H.; Engler, E. M.; Kramer, S. R.; Chambers, J. Q., J. Am. Chem. Soc. 1980, 102 (2), 483-488. [5]       Nakahara, K.; Iwasa, S.; Satoh, M.; Morioka, Y.; Iriyama, J.; Suguro, M.; Hasegawa, E., Chem. Phys. Lett. 2002, 359 (5–6), 351-354. [6]       Nishide, H.; Iwasa, S.; Pu, Y.-J.; Suga, T.; Nakahara, K.; Satoh, M., Electrochim. Acta 2004, 50 (2–3), 827-831. [7]       Nakahara, K.; Iriyama, J.; Iwasa, S.; Suguro, M.; Satoh, M., The Electrochemical Society, Inc. 2004, 206th Meeting, Abs. 435. [8]       Whittingham, M. S., Chem. Rev. 2004, 104 (10), 4271-4302. [9]       Peintinger, M. F.; Beck, J.; Bredow, T., Phys. Chem. Chem. Phys. 2013, 15 (42), 18702-18709. [10]     Lee, D.-Y.; Lee, H.-S.; Kim, H.-S.; Sun, H.-Y.; Seung, D.-Y., Korean J. Chem. Eng. 2002, 19 (4), 645-652. [11]     Placke, T.; Bieker, P.; Lux, S. F.; Fromm, O.; Meyer, H.-W.; Passerini, S.; Winter, M., zpch 2012, 226 (5-6), 391-407. Figure 1