Structural, Ionic, and Electronic Properties of Solid-State Phthalimide-Containing Polymers for All-Organic Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• All-organic batteries require both cathodic and anodic redox-active polymers for solid-state electrodes.
• The development of anodic redox-active polymers is crucial but currently limited.
• Phthalimide-containing polymers are explored as potential anodic materials.

Purpose of the Study:

• To predict the solid-state structural, ionic, and electronic properties of phthalimide-containing polymers for use as anodic materials in all-organic batteries.
• To establish a multiscale approach linking molecular characteristics to macroscopic battery performance.
• To investigate the influence of polymer structure, state of charge, and swelling on transport properties.

Main Methods:

• Utilized a multiscale approach combining atomistic molecular dynamics, electronic structure calculations, and machine learning surrogate models.
• Investigated the impact of different polymer backbones and operational factors (state of charge, swelling).
• Calculated apparent diffusion coefficients of electron transport (D_app) by bridging molecular and condensed-phase properties.

Main Results:

• State of charge significantly affects polymer packing and thermophysical properties, influencing ionic and electronic transport.
• Electron transport capabilities are determined by a combination of molecular (reorganization energy) and condensed-phase (hopping distances) properties.
• Phthalimide-based polymers demonstrated a three-orders-of-magnitude increase in D_app (≈10^-6 cm^2 s^-1) compared to a reference nitroxide radical polymer.

Conclusions:

• Phthalimide-containing polymers are highly promising as anodic materials for all-organic batteries.
• Their exceptional predicted electron transport capabilities are key to their potential.
• The multiscale approach effectively predicts material performance for battery applications.