skip to main content


Title: Reversible epitaxial electrodeposition of metals in battery anodes
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.  more » « less
Award ID(s):
1719875
NSF-PAR ID:
10149172
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Date Published:
Journal Name:
Science
Volume:
366
Issue:
6465
ISSN:
0036-8075
Page Range / eLocation ID:
645 to 648
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract

    The poor reversibility of Zn metal anodes arising from water‐induced parasitic reactions poses a significant challenge to the practical applications of aqueous zinc‐ion batteries (AZIBs). Herein, a novel quasi‐solid‐state “water‐in‐swelling‐clay” electrolyte (WiSCE) containing zinc sulfate and swelling clay, bentonite (BT), is designed to enable highly reversible Zn metal anodes. AZIB full cells based on the WiSCE exhibit excellent cyclic stability at various current densities, long shelf life, low self‐discharge rate, and outstanding high‐temperature adaptability. Particularly, the capacity of WiSCE‐based AZIB full cells retains 90.47% after 200 cycles at 0.1 A g−1, 96.64% after 2000 cycles at 1 A g−1, and 88.29% after 5000 cycles at 3 A g−1. Detailed density functional theory calculations show that strong hydrogen bonds are formed between BT and water molecules in the WiSCE. Thus, water molecules are strongly confined by BT, particularly within the interlayers, which significantly inhibits water‐induced parasitic reactions and greatly improves cyclic stability. Compared to the state‐of‐the‐art “water‐in‐salt” electrolytes, the WiSCE can provide a significantly higher capacity at the full‐cell level with a substantially reduced cost, which is promising for the design of next‐generation high‐performance AZIBs. This work provides a new direction for developing cost‐competitive AZIBs as alternatives to grid‐scale energy storage.

     
    more » « less
  2. In the presence of Lewis acid salts, the cyclic ether, dioxolane (DOL), is known to undergo ring-opening polymerization inside electrochemical cells to form solid-state polymer batteries with good interfacial charge-transport properties. Here we report that LiNO3, which is unable to ring-open DOL, possesses a previously unknown ability to coordinate with and strain DOL molecules in bulk liquids, completely arresting their crystallization. The strained DOL electrolytes exhibit physical properties analogous to amorphous polymers, including a prominent glass transition, elevated moduli, and low activation entropy for ion transport, but manifest unusually high, liquidlike ionic conductivities (e.g., 1 mS/cm) at temperatures as low as −50 °C. Systematic electrochemical studies reveal that the electrolytes also promote reversible cycling of Li metal anodes with high Coulombic efficiency (CE) on both conventional planar substrates (1 mAh/cm2over 1,000 cycles with 99.1% CE; 3 mAh/cm2over 300 cycles with 99.2% CE) and unconventional, nonplanar/three-dimensional (3D) substrates (10 mAh/cm2over 100 cycles with 99.3% CE). Our finding that LiNO3promotes reversibility of Li metal electrodes in liquid DOL electrolytes by a physical mechanism provides a possible solution to a long-standing puzzle in the field about the versatility of LiNO3salt additives for enhancing reversibility of Li metal electrodes in essentially any aprotic liquid electrolyte solvent. As a first step toward understanding practical benefits of these findings, we create functional Li||lithium iron phosphate (LFP) batteries in which LFP cathodes with high capacity (5 to 10 mAh/cm2) are paired with thin (50 μm) lithium metal anodes, and investigate their galvanostatic electrochemical cycling behaviors.

     
    more » « less
  3. Ever-increasing demands for energy, particularly being environmentally friendly have promoted the transition from fossil fuels to renewable energy.1Lithium-ion batteries (LIBs), arguably the most well-studied energy storage system, have dominated the energy market since their advent in the 1990s.2However, challenging issues regarding safety, supply of lithium, and high price of lithium resources limit the further advancement of LIBs for large-scale energy storage applications.3Therefore, attention is being concentrated on an alternative electrochemical energy storage device that features high safety, low cost, and long cycle life. Rechargeable aqueous zinc-ion batteries (ZIBs) is considered one of the most promising alternative energy storage systems due to the high theoretical energy and power densities where the multiple electrons (Zn2+) . In addition, aqueous ZIBs are safer due to non-flammable electrolyte (e.g., typically aqueous solution) and can be manufactured since they can be assembled in ambient air conditions.4As an essential component in aqueous Zn-based batteries, the Zn metal anode generally suffers from the growth of dendrites, which would affect battery performance in several ways. Second, the led by the loose structure of Zn dendrite may reduce the coulombic efficiency and shorten the battery lifespan.5

    Several approaches were suggested to improve the electrochemical stability of ZIBs, such as implementing an interfacial buffer layer that separates the active Zn from the bulk electrolyte.6However, the and thick thickness of the conventional Zn metal foils remain a critical challenge in this field, which may diminish the energy density of the battery drastically. According to a theretical calculation, the thickness of a Zn metal anode with an areal capacity of 1 mAh cm-2is about 1.7 μm. However, existing extrusion-based fabrication technologies are not capable of downscaling the thickness Zn metal foils below 20 μm.

    Herein, we demonstrate a thickness controllable coating approach to fabricate an ultrathin Zn metal anode as well as a thin dielectric oxide separator. First, a 1.7 μm Zn layer was uniformly thermally evaporated onto a Cu foil. Then, Al2O3, the separator was deposited through sputtering on the Zn layer to a thickness of 10 nm. The inert and high hardness Al2O3layer is expected to lower the polarization and restrain the growth of Zn dendrites. Atomic force microscopy was employed to evaluate the roughness of the surface of the deposited Zn and Al2O3/Zn anode structures. Long-term cycling stability was gauged under the symmetrical cells at 0.5 mA cm-2for 1 mAh cm-2. Then the fabricated Zn anode was paired with MnO2as a full cell for further electrochemical performance testing. To investigate the evolution of the interface between the Zn anode and the electrolyte, a home-developed in-situ optical observation battery cage was employed to record and compare the process of Zn deposition on the anodes of the Al2O3/Zn (demonstrated in this study) and the procured thick Zn anode. The surface morphology of the two Zn anodes after circulation was characterized and compared through scanning electron microscopy. The tunable ultrathin Zn metal anode with enhanced anode stability provides a pathway for future high-energy-density Zn-ion batteries.

    Obama, B., The irreversible momentum of clean energy.Science2017,355(6321), 126-129.

    Goodenough, J. B.; Park, K. S., The Li-ion rechargeable battery: a perspective.J Am Chem Soc2013,135(4), 1167-76.

    Li, C.; Xie, X.; Liang, S.; Zhou, J., Issues and Future Perspective on Zinc Metal Anode for Rechargeable Aqueous Zinc‐ion Batteries.Energy & Environmental Materials2020,3(2), 146-159.

    Jia, H.; Wang, Z.; Tawiah, B.; Wang, Y.; Chan, C.-Y.; Fei, B.; Pan, F., Recent advances in zinc anodes for high-performance aqueous Zn-ion batteries.Nano Energy2020,70.

    Yang, J.; Yin, B.; Sun, Y.; Pan, H.; Sun, W.; Jia, B.; Zhang, S.; Ma, T., Zinc Anode for Mild Aqueous Zinc-Ion Batteries: Challenges, Strategies, and Perspectives.Nanomicro Lett2022,14(1), 42.

    Yang, Q.; Li, Q.; Liu, Z.; Wang, D.; Guo, Y.; Li, X.; Tang, Y.; Li, H.; Dong, B.; Zhi, C., Dendrites in Zn-Based Batteries.Adv Mater2020,32(48), e2001854.

    Acknowledgment

    This work was partially supported by the U.S. National Science Foundation (NSF) Award No. ECCS-1931088. S.L. and H.W.S. acknowledge the support from the Improvement of Measurement Standards and Technology for Mechanical Metrology (Grant No. 22011044) by KRISS.

    Figure 1

     

    more » « less
  4. Abstract Lithium metal is a promising anode for energy-dense batteries but is hindered by poor reversibility caused by continuous chemical and electrochemical degradation. Here we find that by increasing the Li plating capacity to high values ( e.g ., 10–50 mAh cm −2 ), Li deposits undergo a morphological transition to produce dense structures, composed of large grains with dominantly (110) Li crystallographic facets. The resultant Li metal electrodes manifest fast kinetics for lithium stripping/plating processes with higher exchange current density, but simultaneously exhibit elevated electrochemical stability towards the electrolyte. Detailed analysis of these findings reveal that parasitic electrochemical reactions are the major reason for poor Li reversibility, and that the degradation rate from parasitic electroreduction of electrolyte components is about an order of magnitude faster than from chemical reactions. The high-capacity Li electrodes provide a straightforward strategy for interrogating the solid electrolyte interphase (SEI) on Li —with unprecedented, high signal to noise. We find that an inorganic rich SEI is formed and is primarily concentrated around the edges of lithium particles. Our findings provide straightforward, but powerful approaches for enhancing the reversibility of Li and for fundamental studies of the interphases formed in liquid and solid-state electrolytes using readily accessible analytical tools. 
    more » « less
  5. Abstract

    Metal anode instability, including dendrite growth, metal corrosion, and hetero-ions interference, occurring at the electrolyte/electrode interface of aqueous batteries, are among the most critical issues hindering their widespread use in energy storage. Herein, a universal strategy is proposed to overcome the anode instability issues by rationally designing alloyed materials, using Zn-M alloys as model systems (M = Mn and other transition metals). An in-situ optical visualization coupled with finite element analysis is utilized to mimic actual electrochemical environments analogous to the actual aqueous batteries and analyze the complex electrochemical behaviors. The Zn-Mn alloy anodes achieved stability over thousands of cycles even under harsh electrochemical conditions, including testing in seawater-based aqueous electrolytes and using a high current density of 80 mA cm−2. The proposed design strategy and the in-situ visualization protocol for the observation of dendrite growth set up a new milestone in developing durable electrodes for aqueous batteries and beyond.

     
    more » « less