A thermal transfer-enhanced zinc anode for stable and high-energy-density zinc-ion batteries

Abstract

Achieving a Zn anode with simultaneous excellent cycling stability and high Zn utilization rate still remains a huge challenge for practical rechargeable zinc-ion batteries. Here, thermal transfer-enhanced layers are coated on both sides of Zn foil, where the top layer enables uniform Zn²⁺ flux and temperature distribution, and the bottom coating improves local heat diffusion and mechanical stability. With such dual thermal protection, thermodynamically driven dendrite growth and side reactions are effectively suppressed. The Zn anode can be stably cycled for 440 h at 5 mA cm⁻²/5 mAh cm⁻² (corresponding to a high Zn utilization rate of 85.5%), which is superior to previously reported results for protective layer-coated zinc anodes. A V₂O₃/N-doped carbon (NC)-based full cell exhibits stable performance for 200 cycles with a high specific energy density (174 Wh kg⁻¹, based on the whole mass of electrodes) and high volumetric energy density (218 Wh L⁻¹, based on the whole cell), which is promising for practical applications.