Triphenylamine-contained multiporous polyimide: Its preparation and application as anode for lithium ion storage

The 3D multiporous structure polyimides were obtained by introducing of the triphenylamine unit as linkage in the pyromellitic-based polyimide (N1) and the naphthalene-1,4,5,8-tetracarboxylic-based polyimides (N2), respectively. Then, the functional polyimides were explored as the anode of Lithium ion batteries instead of as traditional cathode. As a result, the obtained triphenylamine-based polyimides exhibited a good reversible capacity and remarkably improved rate performance. Specially for the porous N1, it delivered a gradually increased capacity of up to 349 mAh g^-1 during the cycle testing and a rate capacity of 400 mAh.g^-1 at an even high current density of 500 mAg^-1. Significant eletrochemical performances for the triphenylamine-contained polyimide could be ascribed to the unique polyimide chemical structure and the constructed 3D multiporous structure with the high surface area (738 m² g^-1 for N1 and 456 m² g^-1 for N2), which benefited to excellent Li⁺ diffusion kinetics in porous electrode. This makes it promising as anode of rechargeable batteries with the remarkably electrochemical performances.