Cellulose Tissue Separator With Aramid-BaTiO₃ Composite Dielectric Coating Proactively Stabilizing Zinc Metal Anodes

A fatal issue of zinc-based electrochemical energy storage (ZEES) is uneven Zn²⁺ deposition and rampant dendrite growth on the zinc metal anode, which significantly reduces the lifespan and reliability of ZEES devices. This work reports a cellulose tissue (CT) based separator with a self-adhesive and nanoporous dielectric coating of aramid nanofibers (ANF) and barium titanate nanoparticles (BTO) to proactively stabilize zinc metal anodes. In this separator (CT-ANF-BTO), the ANF and BTO combine to realize high zincophilicity and pore refinement, while the BTO provides ferroelectric polarization. The benefits of CT-ANF-BTO, as revealed by both experimental results and theoretical calculations, synergistically provide fast/flux-homogenized Zn²⁺ transport, uniform electric field distribution, and low-barrier nucleation, resulting in uniform Zn²⁺ deposition and dendrite-free zinc anodes. Investigation demonstrates that zinc anodes coupled with the CT-ANF-BTO present superior electrochemical stability, whose operation lifetime exceeds 3900, 2400, and 2000 h at 0.5, 1.0, and 2.0 mA cm^-2, respectively. The reliability of the CT-ANF-BTO in both zinc-ion batteries and zinc-ion hybrid supercapacitors is also validated. This work offers a high-performing yet commercially viable cellulose-based separator, which holds significant potential in proactively stabilizing zinc metal anodes for durable and reliable ZEES devices.