# Melem‐Perylene Diimide Polymer Network as Efficient Positive Electrode for Rechargeable Lithium and Magnesium Batteries

## TL;DR

A new organic electrode material was developed for use in rechargeable lithium and magnesium batteries, showing excellent performance and sustainability.

## Contribution

A novel polymer network combining melem and perylene diimide was synthesized and tested as a high-performance organic electrode.

## Key findings

- The Melem-PDI-CNT hybrid material shows excellent cycling stability in Li-ion batteries at high current rates.
- The material exhibits a pseudocapacitive mechanism for Li-ion storage and a diffusion-controlled mechanism for magnesium.
- Classic dyes like PDI can be repurposed for energy storage when integrated into suitable polymer networks.

## Abstract

Organic battery electrode materials represent a sustainable alternative compared to most inorganic electrodes, yet challenges persist regarding their energy density and cycling stability. In this work, a new organic electrode material is described, which is obtained via ionothermal polymerization of low‐cost starting materials, melem (2,5,8‐triamino‐tri‐s‐triazine) and perylenetetracarboxylic dianhydride (PTCDA). The resulting networked polymer Melem‐PDI exhibits favorable thermal and electrochemical properties, prompting investigation into its performance as a positive electrode material in rechargeable lithium and magnesium batteries. A hybrid material with carbon nanotubes (Melem‐PDI‐CNT) is found to exhibit‐excellent cycling stability in Li‐ion batteries at a current rate as high as 500 mA g−1 for 5000 cycles. While the Li‐ion storage is based on a pseudocapacitive mechanism, a diffusion‐controlled mechanism is observed in magnesium batteries. This work underscores that classic dyes (here: PDI) can be repurposed for energy storage, once they are integrated into suitable polymer topologies and brought into nanoscale contact with conductive materials.

An organic electrode combining perylene diimide and heptazine was synthesized in one pot and tested as a positive electrode for lithium and magnesium batteries. The polymer network offers high theoretical capacity. Lithium cells exhibit excellent cycling stability, while magnesium, as a postlithium system, shows promising performance.© 2025 WILEY‐VCH GmbH