Nanofluidic-engineered carbon nanotube ion highways in hydrogels enable high-power aqueous zinc-ion batteries | Science Advances

Quasi-solid polymer electrolytes (QSPEs) for flexible batteries face critical limitations in ion transport efficiency at high currents. We address this with a design of nanofluidic polyacrylamide hydrogel integrating aligned single-walled carbon nanotubes (SWCNTs) as ion highways [SWCNT-embedded polyacrylamide(CPAM)]. Photo-polymerization ensures homogeneous SWCNT distribution, delivering a high ionic conductivity of 30.3 mS cm ⁻¹ while shielding polymer matrices from ion collision. Molecular dynamics simulations identify three ion transport modes, dominated by SWCNT-confined pathways. The CPAM-based Zn||Zn cell exhibits ultralong cycling (7000 hours), and Zn|CPAM|Zn _0.25 V ₂ O ₅ cells retain 80% capacity after 2000 cycles at 40 A g ⁻¹ (19.2 kW kg ⁻¹ ). Cryogenic operation (−15°C) and pouch cells further demonstrate the robust performance of CPAM. This work transcends conventional compromises of QSPEs, enabling wearables with ultrafast charging/discharging, cryogenic tolerance, and mechanical resilience.