A versatile on-substrate electrode setup was developed and used to perform quantitativein operandoEPR as well as low-temperature pulse EPR experiments on electrochemical cells containing a redox conductive polymer as energy-storage material.

Electrochemical cells using LiFePO₄ cathode material are considered one of the safest and most resistant to overcharging among Li-ion batteries. However, if LiFePO₄-based electrodes are exposed to high potentials, surface and structural changes may occur in the electrode material. In this study Li/LiFePO₄ half-cells were overcharged under different modes with variable cut-off voltages and charge currents. The change in voltage profile, discharge capacity, surface layers composition, and crystalline structure were characterized after overcharge cycles. It was demonstrated that the cathode material is resistant to short-term overcharging up to 5 V, but undergoes irreversible changes with increasing overcharge time or potential. Thus, despite the well-known tolerance of LiFePO₄-based batteries to overcharge, a long overcharge time or high cut-off voltage leads to destructive changes in the cathode and should be avoided.

Fe ₄ N active sites supported on porous carbons were prepared and exhibit excellent ORR performance. The Zn–air battery shows a peak power density of 182 mW cm ⁻² and a charge–discharge cycle over 1000 h.

The oxygen reduction reaction (ORR) is a key process for the operation of fuel cells. To accelerate the sluggish kinetics of ORR, a wide range of catalysts have been proposed and tested. In this work, a nano-dispersed copper-impregnated platinum catalyst prepared by electrodeposition of platinum on a poly[Cu(Salen)] template followed by polymer destruction is described. In addition to the high activity of the thus prepared catalyst in the oxygen reduction reaction surpassing that of both polycrystalline platinum catalyst and the commercial carbon-platinum catalyst (“E-TEK”), it showed remarkable tolerance to the presence of methanol in solution.

Safety issues with lithium-ion batteries prevent their widespread use in critical areas of technology. Various types of protective systems have been proposed to prevent thermal runaway and subsequent battery combustion. Among them, thermoresistive systems, representing polymer composites that sharply increase their resistance when the temperature rises, have been actively investigated. However, they are triggered only when the heating of the battery has already occurred, i.e., the system undergoes irreversible changes. This paper describes a new type of protective polymer layer based on the intrinsically conducting polymer poly[Ni(CH₃OSalen)]. The response mechanism of this layer is based on an increase in resistance both when heated and when the cell voltage exceeds the permissible range. This makes it possible to stop undesirable processes at an earlier stage. The properties of the polymer itself and of the lithium-ion batteries modified by the protective layer have been studied. It is shown that the introduction of the polymer protective layer into the battery design leads to a rapid increase of the internal resistance at short circuit, which reduces the discharge current and sharply reduces the heat release. The effectiveness of the protection is confirmed by analysis of the battery components before the short circuit and after it.