h i g h l i g h t s < Free-standing PEDOTeLiFePO 4 composites for lithium ion batteries by dynamic three phase interline electropolymerization. < PEDOTeLiFePO 4 serves as current collector, binder and carbon filler free functional electrodes. < LiFePO 4 mass fraction of 33.5 wt.% in the composite film confirmed by TGA analysis. < The cathode discharge capacity of the PEDOTeLiFePO 4 composite film is 75 mAh g À1 at C/10. a b s t r a c tFree-standing poly(3,4-ethylenedioxythiophene) (PEDOT)eLiFePO 4 composite films were successfully prepared by dynamic three phase interline electropolymerization (D3PIE). These films were used without further modification as the positive electrode in standard lithium ion batteries. As such, this new process eliminates all electrochemically inactive materials (carbon, polymer binder and current collector) used in conventional composite cathodes. The PEDOTeLiFePO 4 composite film offers a discharge capacity of 75 mAh g À1 at the C/10 rate and high capacity retention at the C/2 rate. When reporting this value to the relative amount of LiFePO 4 in the PEDOT-LiFePO 4 composite film, the discharge capacity reached 160 mAh g À1 , close to the theoretical maximum value (170 mAh g À1 ). As such, this approach yield highly functional hybrid free-standing conductive polymer/active material composite cathode with controllable size and structure.

Understanding the key factors that affects overall performances of a battery is crucial to the lithium-ion battery industry. To this end characterisation methods must be specific, reproducible and representative. As such, an interference free and reproducible analytical method with a low detection limit (50 ppb) to evaluate manganese dissolution from lithium-ion battery positive electrodes is presented. Two different electrolytes (1.0 M LiClO4 and 1.0 M LiPF6 in EC:DMC (1:1)), LiFePO4, two nominally similar LiFe0.3Mn0.7PO4 samples and spinel LiMn2O4 are used for proof of concept. Mn and Fe quantification is performed on material ageing in solely in electrolyte, as well as, in a battery system with and without forced oxidation. It is demonstrated that water and free acid content in the electrolyte, as well as, imposing an oxidative electrochemical potential has a profound effect on manganese based material dissolution and battery performance.

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The prolific lithium battery electrode material lithium iron phosphate (LiFePO) stores and releases lithium ions by undergoing a crystallographic phase change. Nevertheless, it performs unexpectedly well at high rate and exhibits good cycling stability. We investigate here the ultrafast charging reaction to resolve the underlying mechanism while avoiding the limitations of prevailing electrochemical methods by using a gaseous oxidant to deintercalate lithium from the LiFePO structure. Oxidizing LiFePO with nitrogen dioxide gas reveals structural changes through in situ synchrotron X-ray diffraction and electronic changes through in situ UV/vis reflectance spectroscopy. This study clearly shows that ultrahigh rates reaching 100% state of charge in 10 s does not lead to a particle-wide union of the olivine and heterosite structures. An extensive solid solution phase is therefore not a prerequisite for ultrafast charge/discharge.

Multilayered graphene (MLG) grown by chemical vapor deposition (CVD) was examined as a negative electrode for lithium-ion batteries. Experimental parameters such as deposition time and temperature were examined to produce carbon loadings between 0.06 -0.17 mg cm -2 and film thicknesses in the 1µm range. The MLG thin films obtained on nickel substrate were used without conductive additive and binding agent in electrochemical tests to produce a capacity of ~250 mAh.g -1 at the 5C rate. Films were further characterized by scanning electron microscopy, atomic force microscopy, grazing angle X-ray diffraction, X-ray photoelectron spectroscopy and Raman micro-spectroscopy mapping. By correlating the structural analysis to the electrochemical properties the importance of edge plane accessibility is emphasized. Separately, a pre and a post deposition treatment were used to improve the electrochemical performances, validating the structural performance limitation hypothesis. In particular, the use of argon plasma post treatment yielded major improvement of the electrochemical performance, which was ascribed to enhanced crystallite edge accessibility.2