High‑performance wide‑temperature zinc‑ion batteries with K+/C3N4 co‑intercalated ammonium vanadate cathodes
As demand for safe and low-cost energy storage grows, aqueous zinc-ion batteries (AZIBs) have emerged as promising candidates. However, their practical application is hindered by cathode instability and poor low-temperature performance. Now, researchers from The Hong Kong Polytechnic University and Shenzhen University, led by Professor Zijian Li, have developed a novel K⁺ and C3N4 co-intercalated NH4V4O10 (KNVO-C3N4) cathode that delivers exceptional performance across a wide temperature range.
Why K⁺/C3N4 Co-Intercalation Matters
Enhanced Reaction Kinetics: The synergistic effect of K⁺ and C3N4 reduces electrostatic interactions and lowers the Zn2+ diffusion barrier.
Structural Stability: Expanded interlayer spacing (10.62 Å) and increased oxygen vacancies improve structural integrity during cycling.
Wide-Temperature Operation: Delivers 111.3 mAh g-1 at −20 °C and 208.6 mAh g-1 at 60 °C, even at 20 A g-1.
Long-Term Durability: Retains 174.2 mAh g-1 after 10,000 cycles at 20 A g-1, with 78.2% capacity retention at 10 A g-1 over 5,000 cycles.
Innovative Design and Features
Tunable Interlayer Spacing: Adjusting C3N4 content optimizes ion transport and mechanical flexibility.
Synergistic Intercalation: K⁺ boosts capacity; C3N4 enhances stability—together they outperform single-intercalation strategies.
Reversible Phase Transitions: Ex situ XRD, Raman, and XPS confirm reversible Zn2+ and H2O co-intercalation without structural collapse.
Pouch Cell Viability: Demonstrates stable performance under bending (0–180°) and powers commercial devices like thermometers.
Applications and Future Outlook
Extreme Environment Energy Storage: Ideal for cold-climate electronics, wearable devices, and grid storage.
Scalable Synthesis: Uses low-cost hydrothermal and stirring methods, suitable for mass production.
Next-Gen Cathode Design: Offers a blueprint for co-intercalation strategies in layered vanadates and beyond.
Challenges and Opportunities: Future work will explore other co-intercalants and optimize electrolytes for even wider temperature ranges.
This work provides a practical and scalable pathway to high-performance, wide-temperature AZIBs. It underscores the power of synergistic material engineering in overcoming long-standing cathode limitations. Stay tuned for more innovations from Professor Zijian Li and his team!
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