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.

Owing to high specific energy, low cost, and environmental friendliness, lithium–sulfur (Li–S) batteries hold great promise to meet the increasing demand for advanced energy storage beyond portable electronics, and to mitigate environmental problems. However, the application of Li–S batteries is challenged by several obstacles, including their short life and low sulfur utilization, which become more serious when sulfur loading is increased to the practically accepted level above 3–5 mg cm−2. More and more efforts have been made recently to overcome the barriers toward commercially viable Li–S batteries with a high sulfur loading. This review highlights the recent progress in high-sulfur-loading Li–S batteries enabled by hierarchical design principles at multiscale. Particularly, basic insights into the interfacial reactions, strategies for mesoscale assembly, unique architectures, and configurational innovation in the cathode, anode, and separator are under specific concerns. Hierarchy in the multiscale design is proposed to guide the future development of high-sulfur-loading Li–S batteries.

Review on High-Loading and High-Energy Lithium–Sulfur Batteries

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 Zn2+ 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/O2-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 MnO2 cathode. The strategy presented here is straightforward and scalable, representing a stark, but promising approach to solve the anode issues in advanced Zn batteries.

Long-life and deeply rechargeable aqueous Zn anodes enabled by a multifunctional brightener-inspired interphase

Lithium-ion batteries, which power portable electronics, electric vehicles, and stationary storage, have been recognized with the 2019 Nobel Prize in chemistry. The development of nanomaterials and their related processing into electrodes and devices can improve the performance and/or development of the existing energy storage systems. We provide a perspective on recent progress in the application of nanomaterials in energy storage devices, such as supercapacitors and batteries. The versatility of nanomaterials can lead to power sources for portable, flexible, foldable, and distributable electronics; electric transportation; and grid-scale storage, as well as integration in living environments and biomedical systems. To overcome limitations of nanomaterials related to high reactivity and chemical instability caused by their high surface area, nanoparticles with different functionalities should be combined in smart architectures on nano- and microscales. The integration of nanomaterials into functional architectures and devices requires the development of advanced manufacturing approaches. We discuss successful strategies and outline a roadmap for the exploitation of nanomaterials for enabling future energy storage applications, such as powering distributed sensor networks and flexible and wearable electronics.

Energy storage: The future enabled by nanomaterials

A passivation layer called the solid electrolyte interphase (SEI) is formed on electrode surfaces from decomposition products of electrolytes. The SEI allows Li+ transport and blocks electrons in order to prevent further electrolyte decomposition and ensure continued electrochemical reactions. The formation and growth mechanism of the nanometer thick SEI films are yet to be completely understood owing to their complex structure and lack of reliable in situ experimental techniques. Significant advances in computational methods have made it possible to predictively model the fundamentals of SEI. This review aims to give an overview of state-of-the-art modeling progress in the investigation of SEI films on the anodes, ranging from electronic structure calculations to mesoscale modeling, covering the thermodynamics and kinetics of electrolyte reduction reactions, SEI formation, modification through electrolyte design, correlation of SEI properties with battery performance, and the artificial SEI design. Multi-scale simulations have been summarized and compared with each other as well as with experiments. Computational details of the fundamental properties of SEI, such as electron tunneling, Li-ion transport, chemical/mechanical stability of the bulk SEI and electrode/(SEI/) electrolyte interfaces have been discussed. This review shows the potential of computational approaches in the deconvolution of SEI properties and design of artificial SEI. We believe that computational modeling can be integrated with experiments to complement each other and lead to a better understanding of the complex SEI for the development of a highly efficient battery in the future.

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Review on modeling of the anode solid electrolyte interphase (SEI) for lithium-ion batteries

Recent Progress of the Solid-State Electrolytes for High-Energy Metal-Based Batteries

Hydrogen peroxide (H2O2) synthesis generally requires substantial postreaction purification. Here, we report a direct electrosynthesis strategy that delivers separate hydrogen (H2) and oxygen (O2) streams to an anode and cathode separated by a porous solid electrolyte, wherein the electrochemically generated H+ and HO2– recombine to form pure aqueous H2O2 solutions. By optimizing a functionalized carbon black catalyst for two-electron oxygen reduction, we achieved >90% selectivity for pure H2O2 at current densities up to 200 milliamperes per square centimeter, which represents an H2O2 productivity of 3.4 millimoles per square centimeter per hour (3660 moles per kilogram of catalyst per hour). A wide range of concentrations of pure H2O2 solutions up to 20 weight % could be obtained by tuning the water flow rate through the solid electrolyte, and the catalyst retained activity and selectivity for 100 hours.

Direct electrosynthesis of pure aqueous H 2 O 2 solutions up to 20% by weight using a solid electrolyte

In light of environmental concerns and energy transition, electrochemical CO2 reduction (ECR) to value-added multicarbon (C2+) fuels and chemicals, using renewable electricity, presents an elegant long-term solution to close the carbon cycle with added economic benefits as well. However, electrocatalytic C─C coupling in aqueous electrolytes is still an open challenge due to low selectivity, activity, and stability. Design of catalysts and reactors holds the key to addressing those challenges. We summarize recent progress in how to achieve efficient C─C coupling via ECR, with emphasis on strategies in electrocatalysts and electrocatalytic electrode/reactor design, and their corresponding mechanisms. In addition, current bottlenecks and future opportunities for C2+ product generation is discussed. We aim to provide a detailed review of the state-of-the-art C─C coupling strategies to the community for further development and inspiration in both fundamental understanding and technological applications.

Strategies in catalysts and electrolyzer design for electrochemical CO2 reduction toward C2+ products

https://cyberleninka.org/article/n/622035.pdf

Progress in electrolytes for rechargeable Li-based batteries and beyond

Developing high-energy lithium-metal batteries (LMBs) as a high priority for next-generation electrochemical energy storage. The unstable solid electrolyte interphase (SEI) formed on the anode and the subsequent nucleation of uneven lithium electrodeposits are now known to be the key limitations to progress in the field. These challenges are shared with multiple other metal anodes, implying that fundamentally-based solutions are broadly interesting. Here, we report a novel strategy of promoting uniform lithium electrodeposition by establishing an artificial SEI layer on the lithium anode via magnetron sputtering deposition. We show by means of density functional theory (DFT) simulations that an artificial SEI enriched in lithium fluoride (LiF) salt provides a low energy barrier (Eb = 0.19 eV in vacuum) for the diffusion of lithium ions, in comparison to SEI components formed spontaneously at the interface by Li reaction with electrolyte components. We also compute the electron localization function (ELF) for Li adsorbates on LiF and show for the first time that degeneracy in the adsorption energy is responsible for the low in-plane diffusion barriers experienced by Li ad atoms on LiF. On this basis we create artificial SEIs based on LiF on Li electrodes and find that the electrodes exhibit exceptional ability to promote smooth Li deposition during charging at a high current density of 1 mA cm−2. Through post-mortem SEM analysis of patterned lithium electrodes, we find visual support for the effectiveness of the artificial SEI. By means of impedance and XPS analyses, we further show that the artificial SEI retains its integrity upon repeated cycles.

Lei Fan

Papers

Recent Progress of the Solid-State Electrolytes for High-Energy Metal-Based Batteries

Direct electrosynthesis of pure aqueous H 2 O 2 solutions up to 20% by weight using a solid electrolyte

Strategies in catalysts and electrolyzer design for electrochemical CO2 reduction toward C2+ products

Progress in electrolytes for rechargeable Li-based batteries and beyond

Regulating Li deposition at artificial solid electrolyte interphases