This comprehensive Review focuses on the key challenges and recent progress regarding sodium-metal anodes employed in sodium-metal batteries (SMBs) The metal anode is the essential component of emerging energy storage systems such as sodium sulfur and sodium selenium, which are discussed as example full-cell applications We begin with a description of the differences in the chemical and physical properties of Na metal versus the oft-studied Li metal, and a corresponding discussion regarding the number of ways in which Na does not follow Li-inherited paradigms in its electrochemical behavior We detail the major challenges for Na-metal systems that at this time limit the feasibility of SMBs The core Na anode problems are the following interrelated degradation mechanisms: An unstable solid electrolyte interphase with most organic electrolytes, "mossy" and "lath-like" metal dendrite growth for liquid systems, poor Coulombic efficiency, and gas evolution Even solid-state Na batteries are not immune, with metal dendrites being reported The solutions may be subdivided into the following interrelated taxonomy: Improved electrolytes and electrolyte additives tailored for Na-metal anodes, interfacial engineering between the metal and the liquid or solid electrolyte, electrode architectures that both reduce the current density during plating-stripping and serve as effective hosts that shield the Na metal from excessive reactions, and alloy design to tune the bulk properties of the metal per se For instance, stable plating-stripping of Na is extremely difficult with conventional carbonate solvents but has been reported with ethers and glymes Solid-state electrolytes (SSEs) such as beta-alumina solid electrolyte (BASE), sodium superionic conductor (NASICON), and sodium thiophosphate (75Na2S·25P2S5) present highly exciting opportunities for SMBs that avoid the dangers of flammable liquids Even SSEs are not immune to dendrites, however, which grow through the defects in the bulk pellet, but may be controlled through interfacial energy modification We conclude with a discussion of the key research areas that we feel are the most fruitful for further pursuit In our opinion, greatly improved understanding and control of the SEI structure is the key to cycling stability A holistic approach involving complementary post-mortem, in situ, and operando analyses to elucidate full battery cell level structure-performance relations is advocated

Sodium Metal Anodes: Emerging Solutions to Dendrite Growth

Generation and Evolution of the Solid Electrolyte Interphase of Lithium-Ion Batteries

Zahlenwerte und Funktionen aus Naturwissenschaften und Technik Von Landolt-Bornstein. Neue Serie. Gesamtherausgabe: K. H. Hellwege. Gruppe II: Atom- und Molekularphysik. Band 1: Magnetische Eigenschaften freier Radikale. Von H. Fischer. Herausgeber: K. H. Hellwege und A. M. Hellwege. Pp. x + 154. (Berlin: Springer-Verlag, 1965.) 68 D.M.

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Electron Spin Resonance

A Growing Appreciation for the Role of LiF in the Solid Electrolyte Interphase

The importance of the solid–electrolyte interphase (SEI) for reversible operation of Li-ion batteries has been well established, but the understanding of its chemistry remains incomplete. The current consensus on the identity of the major organic SEI component is that it consists of lithium ethylene di-carbonate (LEDC), which is thought to have high Li-ion conductivity, but low electronic conductivity (to protect the Li/C electrode). Here, we report on the synthesis and structural and spectroscopic characterizations of authentic LEDC and lithium ethylene mono-carbonate (LEMC). Direct comparisons of the SEI grown on graphite anodes suggest that LEMC, instead of LEDC, is likely to be the major SEI component. Single-crystal X-ray diffraction studies on LEMC and lithium methyl carbonate (LMC) reveal unusual layered structures and Li+ coordination environments. LEMC has Li+ conductivities of >1 × 10−6 S cm−1, while LEDC is almost an ionic insulator. The complex interconversions and equilibria of LMC, LEMC and LEDC in dimethyl sulfoxide solutions are also investigated. The solid–electrolyte-interphase layer is extremely important for reversible electrochemical cycling of Li-ion batteries. Now it has been observed that lithium ethylene mono-carbonate, instead of the previously reported lithium ethylene di-carbonate, is the major initial organic species in this layer and it has a high Li-ion conductivity.

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Identifying the components of the solid-electrolyte interphase in Li-ion batteries.

The anode solid electrolyte interface (SEI) on the anode of lithium ion batteries contains lithium carbonate (Li2CO3), lithium methyl carbonate (LMC), and lithium ethylene dicarbonate (LEDC). The development of a strong physical understanding of the properties of the SEI requires a strong understanding of the evolution of the SEI composition over extended timeframes. The thermal stability of Li2CO3, LMC, and LEDC in the presence of LiPF6 in dimethyl carbonate (DMC), a common salt and solvent, respectively, in lithium ion battery electrolytes, has been investigated to afford a better understanding of the evolution of the SEI. The residual solids from the reaction mixtures have been characterized by a combination of X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy with attenuated total reflectance (IR-ATR), while the solution and evolved gases have been investigated by nuclear magnetic resonance (NMR) spectroscopy and gas chromatography with mass selective detection (GC-MS). The thermal deco...

Decomposition Reactions of Anode Solid Electrolyte Interphase (SEI) Components with LiPF6

Lithium naphthalenide has been investigated as a one electron reducing agent for organic carbonates solvents used in lithium ion battery electrolytes. The reaction precipitates have been analyzed by IR-ATR and solution NMR spectroscopy and the evolved gases have been analyzed by GC-MS. The reduction products of ethylene carbonate and propylene carbonate are lithium ethylene dicarbonate and ethylene and lithium propylene dicarbonate and propylene, respectively. The reduction products of diethyl and dimethyl carbonate are lithium ethyl carbonate and ethane and lithium methyl carbonate and methane, respectively. Lithium carbonate is not observed as a reduction product. © 2014 The Electrochemical Society. [DOI: 10.1149/2.0021409eel] All rights reserved.

Reduction Reactions of Carbonate Solvents for Lithium Ion Batteries

An encapsulated lithium particle (100) including: • a core (110) comprised of at least one of: lithium; a lithium metal alloy; or a combination thereof; and • a shell (120) comprised of a lithium salt, an oil, and optionally a binder, and • the shell encapsulates the core, and the particle size is from 10 to 500 microns. Also, disclosed is a method of making the particle and using the particle in electrical devices such as a capacitor or a battery.

Encapsulated lithium particles and methods of making and use thereof

A carbon-based electrode includes activated carbon, carbon black, and a binder. The binder is fluoropolymer having a molecular weight of at least 500,000 and a fluorine content of 40 to 70 wt. %. A method of forming the carbon-based electrode includes providing a binder-less conductive carbon-coated current collector, pre-treating the carbon coating with a sodium napthalenide-based solution, and depositing onto the treated carbon coating a slurry containing activated carbon, carbon black and binder.

Low resistance ultracapacitor electrode and manufacturing method thereof

A lithium ion energy and power system including: a housing containing: at least three electrodes including: at least one first electrode including a cathodic faradaic energy storage material; at least one second electrode including an anodic faradaic energy storage material; and at least one third electrode including a cathodic non-faradaic energy storage material, wherein the at least one first, second, and third electrodes are adjacent as defined herein, and the at least one second electrode is electrically isolated from the electrically coupled at least one first electrode and the at least one third electrode; a separator between the electrodes; and a liquid electrolyte between the electrodes. Also disclosed is a method of making and using the disclosed lithium ion energy and power system.

Rahul Suryakant Kadam

Papers

Decomposition Reactions of Anode Solid Electrolyte Interphase (SEI) Components with LiPF6

Reduction Reactions of Carbonate Solvents for Lithium Ion Batteries

Encapsulated lithium particles and methods of making and use thereof

Low resistance ultracapacitor electrode and manufacturing method thereof

Integrated energy and power device