Facile Method for Cross-Linking Aromatic Polyamines to Engender beyond Lithium Ion Cathodes for Dual-Ion Batteries

Numerous recent reports on organic-based batteries indicate an emerging interest in dual-ion batteries with polyamine-based cathodes, which are associated with outstanding rate capabilities, high specific capacities, and optimal operation voltages demonstrated by materials of this type. One of the most important and urgent tasks for this research field is the design of polyamine-based materials with advanced performance, as well as the development of methods for their preparation. In this work, a facile cross-linking approach for chemical modification of polymeric aromatic amines, which refines their cathode performance for dual-ion batteries, is presented. The precursor polymers NPDPA and PHTPA were exposed to an additional oxidative polymerization step with ferric chloride to obtain cross-linked (CL) CL-NPDPA and CL-PHTPA materials, respectively. The study of their electrochemical properties in lithium half-cells revealed improved capacities and cycling stabilities for cross-linked polymers, especially for CL-PHTPA; the values of 112.5, 102.6, and 81.1 mAh g–1 were reached under galvanostatic charging and discharging at current densities of 0.1, 1, and 10 A g–1, respectively, thus indicating decent capacities and impressive rate capabilities. The capacity retention of 98 and 36% after 100 and 15 000 cycles, respectively, measured at a current density of 10 A g–1 showed the decent operational stability of lithium batteries. Furthermore, encouraging energy densities of 415, 425, and 211 Wh kg–1 were achieved for CL-PHTPA, while it was applied as a cathode for Na, K, and Mg half-cells, indicating the promise of polyamine materials and the presented cross-linking approach for the development of alternative battery chemistries.