Engineering zincophilic sites on Zn surface via plant extract additives for dendrite-free Zn anode

A brightener-inspired polymer interphase enables highly reversible aqueous Zn anodes via suppressing side-reactions and manipulating the nucleation process. Aqueous Zn anodes have been revisited for their intrinsic safety, low cost, and high volumetric capacity; however, deep-seated issues of dendrite growth and intricate side-reactions hindered their rejuvenation. Herein, a “brightener-inspired” polyamide coating layer which elevates the nucleation barrier and restricts Zn 2+ 2D diffusion is constructed to effectively regulate the aqueous Zn deposition behavior. Importantly, serving as a buffer layer that isolates active Zn from bulk electrolytes, this interphase also suppresses free water/O 2 -induced corrosion and passivation. With this synergy effect, the polymer-modified Zn anode produces reversible, dendrite-free plating/stripping with a 60-fold enhancement in running lifetime (over 8000 hours) compared to the bare Zn, and even at an ultrahigh areal capacity of 10 mA h cm −2 (10 mA cm −2 for 1 h, 85% depth of discharge). This efficient rechargeability for Zn anodes enables a substantially stable full-cell paired with a MnO 2 cathode. The strategy presented here is straightforward and scalable, representing a stark, but promising approach to solve the anode issues in advanced Zn batteries. Show more

The propensity of metals to form irregular and nonplanar electrodeposits at liquid-solid interfaces has emerged as a fundamental barrier to high-energy, rechargeable batteries that use metal anodes. We report an epitaxial mechanism to regulate nucleation, growth, and reversibility of metal anodes. The crystallographic, surface texturing, and electrochemical criteria for reversible epitaxial electrodeposition of metals are defined and their effectiveness demonstrated by using zinc (Zn), a safe, low-cost, and energy-dense battery anode material. Graphene, with a low lattice mismatch for Zn, is shown to be effective in driving deposition of Zn with a locked crystallographic orientation relation. The resultant epitaxial Zn anodes achieve exceptional reversibility over thousands of cycles at moderate and high rates. Reversible electrochemical epitaxy of metals provides a general pathway toward energy-dense batteries with high reversibility. Show more