Lithium-ion batteries have had a profound impact on our daily life, but inherent limitations make it difficult for Li-ion chemistries to meet the growing demands for portable electronics, electric vehicles and grid-scale energy storage. Therefore, chemistries beyond Li-ion are currently being investigated and need to be made viable for commercial applications. The use of metallic Li is one of the most favoured choices for next-generation Li batteries, especially Li-S and Li-air systems. After falling into oblivion for several decades because of safety concerns, metallic Li is now ready for a revival, thanks to the development of investigative tools and nanotechnology-based solutions. In this Review, we first summarize the current understanding on Li anodes, then highlight the recent key progress in materials design and advanced characterization techniques, and finally discuss the opportunities and possible directions for future development of Li anodes in applications.

Reviving the lithium metal anode for high-energy batteries

▪ Abstract Solution phase syntheses and size-selective separation methods to prepare semiconductor and metal nanocrystals, tunable in size from ∼1 to 20 nm and monodisperse to ≤5%, are presented. Preparation of monodisperse samples enables systematic characterization of the structural, electronic, and optical properties of materials as they evolve from molecular to bulk in the nanometer size range. Sample uniformity makes it possible to manipulate nanocrystals into close-packed, glassy, and ordered nanocrystal assemblies (superlattices, colloidal crystals, supercrystals). Rigorous structural characterization is critical to understanding the electronic and optical properties of both nanocrystals and their assemblies. At inter-particle separations 5–100 A, dipole-dipole interactions lead to energy transfer between neighboring nanocrystals, and electronic tunneling between proximal nanocrystals gives rise to dark and photoconductivity. At separations <5 A, exchange interactions cause otherwise insulating ass...

Synthesis and Characterization of Monodisperse Nanocrystals and Close-Packed Nanocrystal Assemblies

The lithium metal battery is strongly considered to be one of the most promising candidates for high-energy-density energy storage devices in our modern and technology-based society. However, uncontrollable lithium dendrite growth induces poor cycling efficiency and severe safety concerns, dragging lithium metal batteries out of practical applications. This review presents a comprehensive overview of the lithium metal anode and its dendritic lithium growth. First, the working principles and technical challenges of a lithium metal anode are underscored. Specific attention is paid to the mechanistic understandings and quantitative models for solid electrolyte interphase (SEI) formation, lithium dendrite nucleation, and growth. On the basis of previous theoretical understanding and analysis, recently proposed strategies to suppress dendrite growth of lithium metal anode and some other metal anodes are reviewed. A section dedicated to the potential of full-cell lithium metal batteries for practical applicatio...

Toward Safe Lithium Metal Anode in Rechargeable Batteries: A Review.

Lithium (Li) metal is an ideal anode material for rechargeable batteries due to its extremely high theoretical specific capacity (3860 mA h g−1), low density (0.59 g cm−3) and the lowest negative electrochemical potential (−3.040 V vs. the standard hydrogen electrode). Unfortunately, uncontrollable dendritic Li growth and limited Coulombic efficiency during Li deposition/stripping inherent in these batteries have prevented their practical applications over the past 40 years. With the emergence of post-Li-ion batteries, safe and efficient operation of Li metal anodes has become an enabling technology which may determine the fate of several promising candidates for the next generation energy storage systems, including rechargeable Li–air batteries, Li–S batteries, and Li metal batteries which utilize intercalation compounds as cathodes. In this paper, various factors that affect the morphology and Coulombic efficiency of Li metal anodes have been analyzed. Technologies utilized to characterize the morphology of Li deposition and the results obtained by modelling of Li dendrite growth have also been reviewed. Finally, recent development and urgent need in this field are discussed.

Lithium metal anodes for rechargeable batteries

Solid-state electrolytes are attracting increasing interest for electrochemical energy storage technologies. In this Review, we provide a background overview and discuss the state of the art, ion-transport mechanisms and fundamental properties of solid-state electrolyte materials of interest for energy storage applications. We focus on recent advances in various classes of battery chemistries and systems that are enabled by solid electrolytes, including all-solid-state lithium-ion batteries and emerging solid-electrolyte lithium batteries that feature cathodes with liquid or gaseous active materials (for example, lithium–air, lithium–sulfur and lithium–bromine systems). A low-cost, safe, aqueous electrochemical energy storage concept with a ‘mediator-ion’ solid electrolyte is also discussed. Advanced battery systems based on solid electrolytes would revitalize the rechargeable battery field because of their safety, excellent stability, long cycle lives and low cost. However, great effort will be needed to implement solid-electrolyte batteries as viable energy storage systems. In this context, we discuss the main issues that must be addressed, such as achieving acceptable ionic conductivity, electrochemical stability and mechanical properties of the solid electrolytes, as well as a compatible electrolyte/electrode interface. This Review details recent advances in battery chemistries and systems enabled by solid electrolytes, including all-solid-state lithium-ion, lithium–air, lithium–sulfur and lithium–bromine batteries, as well as an aqueous battery concept with a mediator-ion solid electrolyte.

Lithium battery chemistries enabled by solid-state electrolytes

Electrical properties of amorphous lithium electrolyte thin films

Fabrication and characterization of amorphous lithium electrolyte thin films and rechargeable thin-film batteries

Amorphous oxide and oxynitride lithium electrolyte thin films were synthesized by r.f. magnetron sputtering of lithium silicates and lithium phosphates in Ar, Ar + O2, Ar + N2, or N2. The composition, structure, and electrical properties of the films were characterized using ion and electron beam, X-ray, optical, photoelectron, and a.c. impedance techniques. For the lithium phosphosilicate films, lithium ion conductivities as high as 1.4 × 10−6 S/cm at 25 °C were observed, but none of these films selected for extended testing were stable in contact with lithium. On the other hand, a new thin-film lithium phosphorus oxynitride electrolyte, synthesized by sputtering Li3PO4 in pure N2, was found to have a conductivity of 2 × 10-6 S/cm at 25 °C and excellent long-term stability in contact with lithium. Thin-films cells consisting of a 1 μm thick amorphous V2O5 cathode, a 1 μm thick oxynitride electrolyte film, and a 5 μm thick lithium anode were cycled between 3.7 and 1.5 V using discharge rates of up to 100 μA/cm2 and charge rates of up to 20 μA/cm2. The open-circuit voltage of 3.6 to 3.7 V of fully-charged cells remained virtually unchanged after months of storage.

https://digital.library.unt.edu/ark:/67531/metadc620220/m2/1/high_res_d/102151.pdf

Thin-film rechargeable lithium batteries

We describe the picosecond nonlinear optical response of a metal-dielectric composite made by implanting Cu ions in fused silica. The implanted Cu ions aggregate during implantation to form nanometer-diameter clusters in a dense, thin (~150 nm) layer just beneath the surface of the substrate. The third-order susceptibility X((3)) has an electronic component with a magnitude of the order of 10(-8) esu and is enhanced for laser wavelengths near the surface plasmon resonance of the copper colloids.

R. A. Zuhr

Papers

Electrical properties of amorphous lithium electrolyte thin films

Fabrication and characterization of amorphous lithium electrolyte thin films and rechargeable thin-film batteries

Fabrication and characterization of amorphous lithium electrolyte thin films and rechargeable thin-film batteries

Thin-film rechargeable lithium batteries

Picosecond nonlinear optical response of a Cu:silica nanocluster composite