Exploring the electrochemistry of PTCDI for aqueous lithium-ion batteries

Aqueous lithium-ion batteries (ALIBs) hold promise of providing cost-effective and safe energy storage in the context of an increasingly environmentally aware narrative. Moreover, mitigating concerns surrounding the critical raw materials present in traditional LIBs reinforces the alignment with such ideals. Herein, we delve into the electrochemistry of perylene-3,4,9,10-tetracarboxylic acid di-imide (PTCDI) and evaluate its potential as an organic anode active material for ALIBs. We find the all-organic anode to very reversibly (de)intercalate Li+ with moderately concentrated aqueous electrolytes, although in a slightly different manner compared with organic solvents. Furthermore, the half-cell electrochemical performance in terms of capacity, capacity retention, rate performance, Coulombic efficiency, and self-discharge, is all indeed satisfactory, where proof-of-concept ALIBs using the high voltage lithium manganese oxide (LMO) exhibit >70 Wh kg−1(PTCDI+LMO) and an average voltage of ca. 1.5 V. These findings have the intention to further encourage organic redox-active material R&D with more dilute aqueous electrolytes, potentially paving the way towards a greener and more sustainable energy landscape.