Ultrathin Surface Coating Enables Stabilized Zinc Metal Anode

Abstract

With the rapid development of energy storage devices, aqueous battery with noncombustion properties and instinct safe features has received great attentions and Zn anode is investigated intensively due to its high theoretical capacity (820 mAh g−1), and low negative potential (−0.762 V vs SHE). However, the unavoidable gas evolution hinders the cyclability and the application in the commercial field. Herein, the atomic layer deposition of TiO2 coating is first demonstrated as the protection layer of metallic zinc anode. The corrosion of zinc plate is significantly suppressed, leading to less gas evolution and Zn(OH)2 byproduct formation. The reduced gas generation on the outer surface of the zinc plate will maintain the effective contact area between the electrolyte and anode and leads to an improved coulombic efficiency. In this way, the Zn anode with 100 ALD cycles TiO2 protection shows reduced overpotential (72.5 mV) at 1 mA cm−2 for Zn–Zn symmetrical battery and additionally, the protection of TiO2 extended the Zn–MnO2 battery cycling performance up to 1000 cycles with the capacity retention of 85% at current density of 3 mA cm−2. The novel design of atomic layer deposition protected metal zinc anode brings in new opportunities to the realization of the ultrasafe aqueous zinc metal batteries.

Do Zinc Dendrites Exist in Neutral Zinc Batteries: A Developed Electrohealing Strategy to In Situ Rescue In‐Service Batteries

“…This decayed cycling performance is attributed to the internal short circuit as symbolized by the sharp decrease of voltage hysteresis . A sudden fluctuation happens after 4 h and rapidly ran well again in Figure c is attributed to the transient change of the circumstance, which has been also reported in previous works . Even worse, this dissatisfactory lifespan further decreased to only ≈2.1 and 1.2 h when elevating the current densities to 7.5 and 10 mA cm −2 (Figure d,e).…”

Toward High‐Performance Hybrid Zn‐Based Batteries via Deeply Understanding Their Mechanism and Using Electrolyte Additive

“…Apparently, the surface of the fresh Zn foil is smooth and flat with some stripes produced possibly by its manufacturing process. Accumulated Zn dendrites were clearly found without additive (Figure b and Figure S8a, Supporting Information), indicating that the Zn dendrites were generated on the surface and further grew in a flake shape . Moreover, a similar morphology of the Zn dendrites was also observed on the Zn foil anode that was stripped out of the Zn/LFP battery after 100 cycles (Figure S9, Supporting Information).…”

“…The growth of Zn dendrites during the plating/stripping process not only causes the “loss” of reversible capacity, but also leads to seriously fading of the Coulombic efficiency and cycle life. Even worse, Zn dendrites normally grow up in the direction perpendicular to the surface of Zn metal, which is a potential safety hazard due to internal shorting failure of the battery after they pierce the separator . On the other hand, the wetting property of the electrode in aqueous media is limited, which has a severely impact on ion diffusion at the interface of electrode and electrolyte .…”

Zinc–air batteries: are they ready for prime time?

“…Wrapping Zn or ZnO with thin protective layers (e.g., GO, TiN x O y and TiO 2 ) to form core/shell structures has been pursued in the literature. 28,29,[62][63][64][65] For example, Liu and coworkers reported ion-sieving carbon nanoshell coated ZnO nanoparticles as the starting anode material of Zn-air batteries. 65 The microporous carbon shell suppressed the dissolution of zincate ions but allowed smaller hydroxide ions to pass freely.…”