Dual-strategy coupling driven versatile carbon-based anode for potassium-ion/potassium metal storage

Reasonably constructed carbon-based electrodes are highly crucial for designing high-performance potassium-ion and potassium metal batteries (PIBs or PMBs). To this end, we developed a Tetramethylol Acetylenediurea derived versatile carbon with rational design of multi-pronged active sites, superior kinetics and robust stability via unique nanoengineering strategies. Specifically, in situ characterizations (e.g., in-situ EIS and in-situ Raman) and theory calculations further unveiled the fundamentals of storage mechanisms. As a result, it delivered high rate capability, remarkable long-term cycling performance for over 2,400 cycles at 1 A/g, high areal capacity of 2.7 mAh cm⁻² at a high mass loading of 8 mg cm⁻² and low potassium nucleation overpotential (14.9 mV at 1 mA cm⁻²). Moreover, the potassium-ion full-cell battery pairing with an organic perylene-3,4,9,10-tetracarboxylic dianhydride cathode enabled ultrahigh energy density of 311.8 Wh kg⁻¹, proving a representing advances in high-performance and stable potassium-based storage.