Synergistic Zn ²⁺ desolvation and diffusion acceleration for high-performance aqueous zinc batteries at low temperature

Aqueous zinc batteries (AZBs) suffer from severe performance degradation at subzero temperatures due to sluggish Zn²⁺ desolvation kinetics, limited ion diffusion, and structural instability of conventional cathodes. Herein, phenylbutylamine (PBA) molecules are intercalated into layered V₂O₅ to construct VO-PBA with dual-functional mechanisms for low-temperature AZBs. The pre-intercalated PBA molecules act as structural pillars to expand the interlayer spacing, significantly enhancing Zn²⁺ diffusion kinetics. Simultaneously, VO-PBA facilitates the desolvation of [Zn(H₂O)₆]²⁺ by lowering the desolvation energy barrier, thereby mitigating excess H₂O insertion. Density functional theory calculations further confirm smoother Zn²⁺ migration pathways and enhanced electronic conductivity in VO-PBA. Leveraging these synergistic effects, the VO-PBA cathode achieves exceptional low-temperature performance, delivering a high capacity of 201 mAh g^-1 at 0.1 A g^-1 and nearly no capacity fading over 1000 cycles at 1 A g^-1 at -30 °C. This work provides a simple cathode optimization paradigm for low-temperature AZBs.