The early-stage growth and reversibility of Li electrodeposition in Br-rich electrolytes.

The physiochemical nature of reactive metal electrodeposits during the early stages of electrodeposition is rarely studied but known to play an important role in determining the electrochemical stability and reversibility of electrochemical cells that utilize reactive metals as anodes. We investigated the early-stage growth dynamics and reversibility of electrodeposited lithium in liquid electrolytes infused with brominated additives. On the basis of equilibrium theories, we hypothesize that by regulating the surface energetics and surface ion/adatom transport characteristics of the interphases formed on Li, Br-rich electrolytes alter the morphology of early-stage Li electrodeposits; enabling late-stage control of growth and high electrode reversibility.

Designing Polymeric Interphases for Stable Lithium Metal Deposition.

Reactive metals are known to electrodeposit with irregular morphological features on planar substrates. A growing body of work suggest that multiple variables: composition, mechanics, structure, ion transport properties, reductive stability, and interfacial energy of interphases, formed either spontaneously or by design on the metal electrode play important but differentiated roles in regulating these morphologies. We examine the effect of fluorinated thermoset polymer coatings on Li deposition by means of experiment and theoretical linear stability analysis.

Rechargeable Lithium Metal Batteries with an In-Built Solid-State Polymer Electrolyte and a High Voltage/Loading Ni-Rich Layered Cathode.

Solid-state batteries enabled by solid-state polymer electrolytes (SPEs) are under active consideration for their promise as cost-effective platforms that simultaneously support high-energy and safe electrochemical energy storage. The limited oxidative stability and poor interfacial charge transport in conventional polymer electrolytes are well known, but difficult challenges must be addressed if high-voltage intercalating cathodes are to be used in such batteries. Here, ether-based electrolytes are in situ polymerized by a ring-opening reaction in the presence of aluminum fluoride (AlF ) to create SPEs inside LiNi Co Mn O (NCM) || Li batteries that are able to overcome both challenges.

Nucleation and Early Stage Growth of Li Electrodeposits.

The morphologies that metal electrodeposits form during the earliest stages of electrodeposition are known to play a critical role in the recharge of electrochemical cells that use metals as anodes. Here we report results from a combined theoretical and experimental study of the early stage nucleation and growth of electrodeposited lithium at liquid-solid interfaces. The spatial characteristics of lithium electrodeposits are studied via scanning electron microscopy (SEM) in tandem with image analysis.

Solid-state polymer electrolytes for high-performance lithium metal batteries.

Electrochemical cells based on alkali metal anodes are receiving intensive scientific interest as potentially transformative technology platforms for electrical energy storage. Chemical, morphological, mechanical and hydrodynamic instabilities at the metal anode produce uneven metal electrodeposition and poor anode reversibility, which, are among the many known challenges that limit progress. Here, we report that solid-state electrolytes based on crosslinked polymer networks can address all of these challenges in cells based on lithium metal anodes.

Stabilizing polymer electrolytes in high-voltage lithium batteries.

Electrochemical cells that utilize lithium and sodium anodes are under active study for their potential to enable high-energy batteries. Liquid and solid polymer electrolytes based on ether chemistry are among the most promising choices for rechargeable lithium and sodium batteries. However, uncontrolled anionic polymerization of these electrolytes at low anode potentials and oxidative degradation at working potentials of the most interesting cathode chemistries have led to a quite concession in the field that solid-state or flexible batteries based on polymer electrolytes can only be achieved in cells based on low- or moderate-voltage cathodes.

Electroless Formation of Hybrid Lithium Anodes for Fast Interfacial Ion Transport.

Rechargeable batteries based on metallic anodes are of interest for fundamental and application-focused studies of chemical and physical kinetics of liquids at solid interfaces. Approaches that allow facile creation of uniform coatings on these metals to prevent physical contact with liquid electrolytes, while enabling fast ion transport, are essential to address chemical instability of the anodes. Here, we report a simple electroless ion-exchange chemistry for creating coatings of indium on lithium.