Abstract: Described herein are carbon-silicon composite structures and methods of producing such structures. A carbon-silicon composite structure comprises one or more carbon-containing structures that have pores at least partially filled with silicon-containing structures. Specifically, the silicon-containing structures are attached to the pore walls while maintaining void spaces within these pores. These void spaces can accommodate silicon expansion during lithiation. Carbon-silicon composite structures can be produced by submerging carbon-containing structures into a precursor liquid solution (comprising a precursor) and driving this solution into the pores. The silicon-containing structures are then formed (from the precursor) within the pores either electrochemically (e.g., by applying a voltage to the solution and structures) or chemically (e.g., by introducing the structures into a reducing liquid solution). In some examples, these void spaces are sealed from the environment by additional structures, e.g.

Abstract: Provided are methods of forming active materials for electrochemical cells using low-temperature electrochemical deposition, e.g., less than 200° C. Specifically, these processes allow precise control of the morphology, composition, and size of deposited structures. For example, the deposited structure may be doped, alloyed, or surface treated during their deposition using a combination of different precursors. In particular, silicon structure may be pre-lithiated while these structures are being formed. The selection of working electrodes (surface size and properties), electrolyte composition, and other parameters result in different types of structures, e.g., precipitating from the electrolyte or deposited on the electrode. Low-temperature plating does not require a lot of energy and volatile and invisible precursors. Furthermore, this plating produces a more confined waste stream, suitable for post-reaction recycling.

Abstract: Provided are methods of forming active materials for electrochemical cells using low-temperature electrochemical deposition, e.g., less than 200° C. Specifically, these processes allow precise control of the morphology, composition, and size of deposited structures. For example, the deposited structure may be doped, alloyed, or surface treated during their deposition using a combination of different precursors. In particular, silicon structure may be pre-lithiated while these structures are being formed. The selection of working electrodes (surface size and properties), electrolyte composition, and other parameters result in different types of structures, e.g., precipitating from the electrolyte or deposited on the electrode. Low-temperature plating does not require a lot of energy and volatile and invisible precursors. Furthermore, this plating produces a more confined waste stream, suitable for post-reaction recycling.

Abstract: Compositions and processes for forming barrier coatings to prevent hydrogen embrittlement of an underlying material are disclosed. The coating can be made up of composite structures of metal and oxide that are alternately deposited onto a substrate for creating a multilayer coated substrate. Such multilayer coating can be incorporated into many contexts in which hydrogen permeation prevention is desired, such as pipelines and manufacture of advanced automotive steels. The process involves depositing a metal layer onto the substrate followed by a metal oxide layer thereon. The interface of the metal layer and the oxide layer can form space-charge zones that decrease hydrogen permeability therethrough.

Abstract: Systems and methods for regulating hydrogen concentration in structural materials by electrochemically controlling hydrogen desorption to promote recovery from hydrogen embrittlement are disclosed. Embrittled material can be exposed to an electrolyte and a counter electrode to set up a potential across the material to induce the electrochemical oxidation of atomic hydrogen (H) in the surface of the material. Oxidation reduces hydrogen concentration near the surface, increases hydrogen diffusion toward the surface, and eventually accelerates hydrogen desorption through and out of the material. In some embodiments, a catalyst can be applied to the surface of the material to return the material to its original state before embrittlement.

Abstract: Described herein are composite battery electrode structures and methods of forming such structures. Composite battery electrode structures comprise active electrode material structures and polymer structures such that at least a portion of the polymer structures at least partially protrudes into some of the high capacity structures. Some of these polymer structures may be fully enclosed by the active electrode material structures. Other polymer structures may only partially extend inside the active electrode material structures. Furthermore, additional polymer structures may be bound to the external surface of the active electrode material structures. Composite battery electrode structures may be formed using low-temperature deposition techniques, such as solvent-thermal synthesis, direct chemical reduction, and electrochemical deposition. More specifically, composite battery electrode structures may be formed from a solution comprising active electrode material precursors and polymer precursors, e.g.

Abstract: The present invention demonstrates Br2-based conversion chemistry is a potential route toward rechargeable Mg-batteries. Compared with Mg-ion or Mg-air chemistries, the Mg—Br2 system features fast kinetics and good cyclability. In one embodiment, the present invention provides a rechargeable non-aqueous, dual-electrolyte scheme. In one embodiment, the anolyte consisted of Mg(TFSI)2 dissolved in a monoglyme and diglyme mixture, whereas the catholyte was composed of Mg(TFSI)2 in PYR14TFSI ionic liquid mixed with active bromine species. When Mg was used as the anode, an open circuit voltage of 3.0 V (vs. Mg2+/Mg) was measured.

Abstract: The present invention demonstrates Br2-based conversion chemistry is a potential route toward rechargeable Mg-batteries. Compared with Mg-ion or Mg-air chemistries, the Mg—Br2 system features fast kinetics and good cyclability. In one embodiment, the present invention provides a rechargeable non-aqueous, dual-electrolyte scheme. In one embodiment, the anolyte consisted of Mg(TFSI)2 dissolved in a monoglyme and diglyme mixture, whereas the catholyte was composed of Mg(TFSI)2 in PYR14TFSI ionic liquid mixed with active bromine species. When Mg was used as the anode, an open circuit voltage of 3.0 V (vs. Mg2+/Mg) was measured.

Abstract: The invention provides a unique catalyst system without the need for carbon. Metal nanoparticles were grown onto conductive, two-dimensional material of TiSi2 nanonet by atomic layer deposition. The growth exhibited a unique selectivity with the elemental metal deposited only on defined surfaces of the nanonets in nanoscale without mask or patterning.