Abstract: Described herein are electrochemically active-material structures comprising high-capacity materials. The mean largest cross-sectional dimension of these structures is kept below the pulverization threshold, which corresponds to the structures' composition. As such, the structure fracturing during battery cycling is reduced thereby preserving the battery capacity. Furthermore, these structures have a sphericity of at least about 0.9. Such high sphericity values translate into a small surface area for a given volume thereby reducing the electrolyte decomposition and solid electrolyte interphase (SEI) formation on the surface of these structures. Furthermore, the small size and high sphericity help to keep swelling substantially isotropic nature. The small structure size also helps with preserving the initially formed SEI layer thereby limiting this SEI formation to initial cycles.

Abstract: Provided are layered gel-polymer electrolytes and electrochemical cells comprising these electrolytes as well as methods of forming the electrolytes and the cells. A gel-polymer electrolyte comprises a support core and one or two interface layers on the core surface. The interface layers are relied on to conform to electrode surfaces with high surface roughness, while the support core prevents any physical penetration and electrical shorts through the gel-polymer electrolyte, e.g., by electrode protruding peaks. Specifically, the interface layer redistributes around these protruding peaks and forms a continuous interface with the electrode surface. When the stack is compressed, the gel-polymer electrolyte also releases some liquid electrolyte, which soaks the electrode and enhances ionic transfer within the electrode and through the electrolyte-electrode interface. The gel-polymer electrolyte is formed by coating interface layers on the support core and soaking this assembly in a liquid electrolyte.

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: Described herein are electrochemically active-material structures comprising silicon and one or more inert elements, such that these inert elements are chemically and/or atomically dispersed. Also described are negative battery electrodes and lithium-ion electrochemical cells comprising such electrochemically active-material structures as well as methods of fabricating such structures, electrodes, and lithium-ion electrochemical cells. Some examples of atomically-dispersed inert elements include, but are not limited to, hydrogen (H), carbon (C), nitrogen (N), and chlorine (Cl). Unlike silicon, inert elements do not interact with lithium at an operating voltage of the negative battery electrode and therefore do not contribute to the overall cell capacity. At the same time, these inert elements help to mitigate silicon swelling by operating as a mechanical buffer, support structure, and/or additional conductive pathways.

Abstract: Described herein are methods for producing silicon-containing structures using electrochemically generated solutions and chemical reduction of components in such solutions. For example, a cathode solution and an anode solution may be provided a reactor with the cathode solution comprising a cathode solution solvent, a cathode solution salt, and a redox mediator and with the anode solution comprising an anode solution solvent and an anode solution salt. A voltage is then applied between the cathode and anode thereby converting the redox mediator into a reducing agent forming a charged cathode solution. The method may proceed with adding a silicon-containing precursor to the charged cathode solution such that the reducing agent reacts with the silicon-containing precursor and forms silicon-containing structures and a precursor-mixture salt in the precursor mixture. The redox mediator is released into the precursor mixture during this operation.

Abstract: Described herein are electrochemically active-material structures comprising silicon and one or more inert elements, chemically and/or atomically dispersed in these electrochemically active-material structures. Also described are negative battery electrodes and lithium-ion electrochemical cells comprising such electrochemically active-material structures as well as methods of fabricating such structures, electrodes, and lithium-ion electrochemical cells. Some examples of atomically-dispersed inert elements include, but are not limited to, hydrogen (H), carbon (C), nitrogen (N), and chlorine (Cl). Unlike silicon, inert elements do not interact with lithium at an operating voltage of the negative battery electrode and therefore do not contribute to the overall cell capacity. At the same time, these inert elements help to mitigate silicon swelling by operating as a mechanical buffer, support structure, and/or additional conductive pathways.

Abstract: Described herein are electrochemically active-material structures comprising silicon and one or more inert elements, such that these inert elements are chemically and/or atomically dispersed. Also described are negative battery electrodes and lithium-ion electrochemical cells comprising such electrochemically active-material structures as well as methods of fabricating such structures, electrodes, and lithium-ion electrochemical cells. Some examples of atomically-dispersed inert elements include, but are not limited to, hydrogen (H), carbon (C), nitrogen (N), and chlorine (Cl). Unlike silicon, inert elements do not interact with lithium at an operating voltage of the negative battery electrode and therefore do not contribute to the overall cell capacity. At the same time, these inert elements help to mitigate silicon swelling by operating as a mechanical buffer, support structure, and/or additional conductive pathways.

Abstract: Provided are methods of forming active materials for electrochemical cells using low-temperature electrochemical deposition, e.g., at less than 200° C. Specifically, these processes allow precise control of the morphology, composition, and/or size of the deposited structures. For example, a deposited structure may be doped, alloyed, or surface treated during its formation using a combination of different precursors. In particular, a silicon structure may be prelithiated while being formed. Different working electrodes (e.g., with different surface sizes and properties) allow forming different types of structures, e.g., precipitating particles from the solution or specific types of films deposited on the working electrode. These processes require minimal energy and do not use volatile precursors. Furthermore, these processes produce a more confined waste stream, suitable for post-reaction recycling. Finally, low-temperature electrochemical deposition can be readily scaled up.

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 layered gel-polymer electrolytes and electrochemical cells comprising these electrolytes as well as methods of forming the electrolytes and the cells. A gel-polymer electrolyte comprises a support core and one or two interface layers on the core surface. The interface layers are relied on to conform to electrode surfaces with high surface roughness, while the support core prevents any physical penetration and electrical shorts through the gel-polymer electrolyte, e.g., by electrode protruding peaks. Specifically, the interface layer redistributes around these protruding peaks and forms a continuous interface with the electrode surface. When the stack is compressed, the gel-polymer electrolyte also releases some liquid electrolyte, which soaks the electrode and enhances ionic transfer within the electrode and through the electrolyte-electrode interface. The gel-polymer electrolyte is formed by coating interface layers on the support core and soaking this assembly in a liquid electrolyte.

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 new solid-state electrochemical cells and methods for fabricating these cells. In some examples, a solid-state electrochemical cell is assembled using a negative electrode, a positive electrode, and a gel-polymer electrolyte layer, which is disposed and provides ionic communications between these electrodes. Prior to this assembly, the negative electrode is free from electrolytes. The negative electrode is fabricated using a coating technique, e.g., forming a slurry, comprising a polymer binder and one or more negative active materials structures, such as silicon, graphite, and the like. The porosity, size, and other characteristics of the negative active materials structures and of the resulting coated later are specifically controlled to ensure operation with the gel-polymer electrolyte layer or, more specifically, high-rate charge and discharge, e.g., greater than 1 mA/cm2.

Abstract: Provided are methods for solid state pretreatment of active materials (e.g., prelithiation of silicon monoxide) while forming treated negative active material structures. Also provided are the formed structures, negative electrodes comprising these structures, and electrochemical cells comprising these electrodes. In some examples, silicon monoxide structures are mixed with lithium hydroxide structures or some other lithium-containing structures. The mixture is heated in an inert environment to form treated negative active material structures. These treated structures comprise various lithium-containing components, some of which trap lithium. When an electrochemical cell, formed with these treated negative active material structures, is initially charged and additional new lithium ions are introduced into the negative electrodes (e.g.

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: Provided are electrodes for use in electrochemical cells and active material components used to form these electrodes. Also provided are methods of forming these active material components as well as methods of forming these electrodes. An electrode comprises a current collector and an active layer, comprising active material structures and an inorganic conductive layer. The inorganic conductive layer coats and binds together these active material structures. Furthermore, the inorganic conductive layer also provides adhesion of the active layer to the current collector. The inorganic conductive layer has an electronic conductivity of at least 104 S/m and provides an electronic path among the active material structures and, in some examples, between the active material structures and the current collector. In some embodiments, the same inorganic conductive layer shared by multiple active material structures.

Abstract: Provided are methods of introducing additional lithium ions into lithium-ion electrochemical cells as well as positive electrodes, comprising these additional lithium ions. A method may involve introducing a temporary lithium additive into a positive electrode, such as mixing the additive into slurry used for coating the electrode. The positive electrode also comprises a positive active material, different from the temporary lithium additive and used as a source of primary lithium ions. The positive active material is operable to release and also later to receive lithium ions during cycling. The temporary lithium additive is operable to release additional lithium ions during its decomposition, but not to receive any lithium ions thereafter. The amount of these additional lithium ions may be selected based on expected lithium ion losses in the cell. The temporary lithium additive may decompose when applying a voltage between the electrodes, e.g., during initial cycling.

Abstract: Provided are hybrid active material structures for use in electrodes of electrochemical cells and methods of forming these structures. A hybrid active material structure comprises at least one first substructure and at least one second substructures, each comprising a different layered active material and interfacing each other. Combining multiple layered active materials into the same structure and arranging these materials in specific ways allow achieving synergetic effects of their desirable characteristics. For example, a layered active material, which forms a stable solid electrolyte interface (SEI) layer, may be form an outer shell of a hybrid active material structure and interface with electrolyte. This shell may surround another layered active material, which has a higher capacity but would otherwise forma a less stable SEI layer. Furthermore, multiple layered active materials may be arranged into a stack, in which one of these materials may operate as an ionic and/or electronic conductor.

Abstract: Provided are methods of introducing additional lithium ions into lithium-ion electrochemical cells as well as positive electrodes, comprising these additional lithium ions. A method may involve introducing a temporary lithium additive into a positive electrode, such as mixing the additive into slurry used for coating the electrode. The positive electrode also comprises a positive active material, different from the temporary lithium additive and used as a source of primary lithium ions. The positive active material is operable to release and also later to receive lithium ions during cycling. The temporary lithium additive is operable to release additional lithium ions during its decomposition, but not to receive any lithium ions thereafter. The amount of these additional lithium ions may be selected based on expected lithium ion losses in the cell. The temporary lithium additive may decompose when applying a voltage between the electrodes, e.g., during initial cycling.

Abstract: Provided are electrodes for use in electrochemical cells and active material components used to form these electrodes. Also provided are methods of forming these active material components as well as methods of forming these electrodes. An electrode comprises a current collector and an active layer, comprising active material structures and an inorganic conductive layer. The inorganic conductive layer coats and binds together these active material structures. Furthermore, the inorganic conductive layer also provides adhesion of the active layer to the current collector. The inorganic conductive layer has an electronic conductivity of at least 104 S/m and provides an electronic path among the active material structures and, in some examples, between the active material structures and the current collector. In some embodiments, the same inorganic conductive layer shared by multiple active material structures.