posted on 2021-03-03, 21:14authored byRoman R. Kapaev, Alexey G. Scherbakov, Alexander F. Shestakov, Keith J. Stevenson, Pavel A. Troshin
Organic
compounds have recently gained significant attention as
materials for the next generation of sustainable energy storage devices.
Polyimides are one of the most attractive types of organic battery
cathode materials, especially if they are produced from easily accessible,
inexpensive reagents. However, these polymers are still at the early
stage of development for rechargeable metal-ion batteries. Particularly,
the scope of amine building blocks that were used for the polyimide
synthesis remains scarce. In this study, we propose m-phenylenediamine as a building block for polyimide-based cathode
materials. We report the electrochemical properties of polyimides
obtained from 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA)
and m- or p-phenylenediamines for
lithium-, sodium-, and potassium-ion batteries; and show that the m-polyimide has several advantages over the p-isomer. It has larger capacities and superior high-rate capabilities,
owing to a higher specific surface area and smaller particle size.
In sodium- and potassium-based batteries, the redox potentials of
the m-isomer are higher because of the spatial arrangement
of adjacent imide units, which makes chelation of metal cations more
energetically favorable. These results provide an impetus for designing
new polyimide-based battery materials with higher energy density and
fast charge–discharge kinetics.