Research and development of lithium-ion batteries (LIBs) has gathered a great deal of momentum in the last two decades due to their potential promising applications in portable electronics and electric vehicles. This is partly due to rapid advancement of inorganic intercalation compounds and carbon-involved composite electrode materials. However, albeit their substantial success, in present commercial LIBs, the urgent need for cost-effective, large-scale, safe, and sustainable battery technologies feeds an ever-growing quest for alternative energy related materials. In this context, substituting traditional metal oxide-based intercalation compounds with organic electrode materials (OEMs) with electroactive organic redox functionalities has attracted the attention of researchers due to the greater abundance of organic compounds, huge synthetic possibilities, lower cost, and safety and sustainability aspects.[1]

Among the different types of OEMs, redox-active polymers (RAPs) are materials of choice due to their high structural diversity, rich and tunable electrochemistry, etc.[2] However, their high electrochemical performance is primarily linked to the use of low polymer mass-loading electrodes (typically below 2 mg cm⁻²) with a high carbon-additives content (20–80 wt%) that together hinders their practicability in real batteries.[3–5] In my oral presentation, I will present an interesting strategy to develop high performance and practical naphthalene-tetracarboxylic dianhydride-derived polyimide (PI) electrodes that are processed into buckypaper electrodes without binder and current collector. This effective electrode fabrication method enables high-mass-loading composite electrodes (up to 55 mg cm⁻²) with low carbon-additive content (20 wt %), which attained high gravimetric (170 mAh g⁻¹), areal (8.5 mAh cm⁻²) and volumetric (205 mAh cm⁻³) capacities with good rate capability (1.6 mAh cm⁻² at 5C; 25 mA cm⁻²) in Li-ion half-cells. To the best of our knowledge, these are most probably the highest values reported for an organic electrode in Li-ion batteries, constituting a great leap forward in the development of practical organic batteries. As a proof of concept, semi-organic full cells were assembled in Li_Graphite||PI, Li_LTO||PI, PI||LFP, and PI||NMC configurations in both coin-type and pouch-type cell prototypes to assess the practicality of these high-mass-loading PI electrodes. Electrochemical performance metrics in terms of capacity, energy and power density (gravimetric, volumetric, and areal) of these full cells were evaluated, along with preliminary cost prediction of practical Li ion batteries for e-mobility application.[6] Both performance metrics (32 mWh cm⁻²) and cost factors (98$ kWh⁻¹) for the presented redox polymer were favourable that could have great prospects for future practical (semi)organic batteries. I believe that this study may be of broad interest to the audience of the conference, providing insights for the development of practical and sustainable energy storage solutions.