Co-Optimized Potassium Deposition and Interfacial Stability Enabled by 3D-Printed GO/ATP Hosts for Durable...

Potassium metal batteries (PMBs) are promising candidates for next-generation large-scale energy storage owing to their high energy density and cost-effectiveness. However, their rate capability and cycling stability are severely hindered by sluggish K⁺ transport kinetics, uncontrolled dendrite growth, and fragile solid electrolyte interphase (SEI) at the K anode. Herein, a hierarchically porous three-dimensional (3D) host integrating graphene oxide (GO) and attapulgite (ATP) is fabricated by direct ink writing (denoted 3DP-GO/ATP), combining strong potassiophilicity with anion affinity. Its interconnected porous architecture provides continuous ion-transport pathways, facilitating rapid K⁺ transport. The potassiophilic sites lower the K nucleation barrier and promote dendrite-free K deposition, whereas the strong anion affinity drives interfacial FSI- enrichment and favors the formation of an inorganic-rich SEI. The resulting K||3DP-GO/ATP asymmetric batteries deliver stable cycling for 2750 cycles (5500 h), while the 3DP-GO/ATP@K||3DP-GO/ATP@K symmetric batteries sustain stable operation for over 3750 h at 0.5 mA cm^-2/0.5 mAh cm^-2. When paired with a perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) cathode, the full batteries retain a reversible capacity of 93.56 mAh g^-1 after 1000 cycles at 20C and remain reversibly operational at 100C. This strategy enables synergistic regulation of K deposition and interfacial chemistry, promoting high-rate and long-life PMBs.