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The application areas of rechargeable Li-ion batteries continue to grow, hence improvement in their energy density, rate capability and cycle life is necessary. A typical cathode contains usually redox active transition metal oxides as active materials, conductive additives to ensure electronic conductivity and binder supporting matrix. In this work we report the behavior and properties of carbon black free LiFePO 4 composite electrode, where poly (3,4-ethylene dioxythiophene): poly (styrene sulfonate) (PEDOT:PSS) is accomplishing a dual role of binder and conducting additive. The effect of the polymer amount on the morphometric properties of the electrodes was studied using SEM, mercury porosimetry and high resolution X-ray computed tomography. The electrochemical performance and the cycling stability of the composite electrodes were compared to the behavior of conventional cathodes with carbon additives and PVDF binder. With increasing PEDOT:PSS content a decrease in the overvoltage and correspondingly an improvement in the rate capability is observed. Composite cathodes containing 8% PEDOT:PSS show comparable electrode capacity and better cyclic stability than conventional composite cathode.

The decay rate of 7 Be has always been measured by either forming a beryllium compound or implanting 7 Be in a medium. We can quantitatively understand the measured changes of 7 Be decay rates in different environments as well as its L/K orbital electron capture ratio using tight-binding linear muffin-tin orbital method calculations. We find that 7 Be loses a very substantial fraction of its 2s electrons in a medium. As a result of this loss of 2s electrons, the extracted nuclear matrix element of the 7 Be electron capture reaction from terrestrial decay rate measurements should increase by 2-2.7%, thus decreasing the calculated 8 B solar neutrino flux from the Standard Solar Model by 2-2.7%.

Water-soluble binders can enable greener and cost-effective Li-ion battery manufacturing by eliminating the standard fluorine-based formulations and associated organic solvents. The issue with water-based dispersions, however, remains the difficulty in stabilizing them, requiring additional processing complexity. Herein, we show that mechanochemical conversion of a regular poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) water-based dispersion produces a hydrogel that meets all the requirements as binder for lithium-ion battery electrode manufacture. We particularly highlight the suitable slurry rheology, improved adhesion, intrinsic electrical conductivity, large potential stability window and limited corrosion of metal current collectors and active electrode materials, compared to standard binder or regular PEDOT:PSS solution-based processing. When incorporating the active materials, conductive carbon and additives with PEDOT:PSS, the mechanochemical processing induces simultaneous binder gelation and fine mixing of the components. The formed slurries are stable, show no phase segregation when stored for months, and produce highly uniform thin (25 μm) to very thick (500 μm) films in a single coating step, with no material segregation even upon slow drying. In conjunction with PEDOT:PSS hydrogels, technologically relevant materials including silicon, tin, and graphite negative electrodes as well as LiCoO, LiMnO, LiFePO, and carbon-sulfur positive electrodes show superior cycling stability and power-rate performances compared to standard binder formulation, while significantly simplifying the aqueous-based electrode assembly.

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The electrodes in Li-ion batteries consist of multiple components such as active materials, conductive additives and polymeric binder. The polymeric binder influences significantly the properties and stability of the composite electrode and the overall battery performance. We proposed the application of poly-3,4-ethylendioxythiophen: polystyrene sulfonic acid (PEDOT:PSS) poly-ion complex as a conductive binder material for cathodes in lithium ion battery. In this paper we report the electrochemical behavior and stability of PEDOT:PSS in battery electrolyte in terms of cyclic voltammetry and electrochemical impedance spectroscopy. The impedance behavior of PEDOT:PSS has been studied at different ambient temperatures and the ionic and electronic conductivities of PEDOT:PSS has been evaluated using a modified transmission line model. PEDOT:PSS shows stable behavior during multiple cycling in the operated potential range up to 4.2 V and no change in the impedance was visible after 200 cycles.