The present application provides a silicon-oxygen composite negative electrode material and a preparation method therefor, and a lithium ion battery. The silicon-oxygen composite negative electrode material has a core-shell structure, the core comprises nano-silicon and a silicon oxide SiO.sub.x, and the shell comprises Li.sub.2SiO.sub.3. The preparation method comprises: mixing a silicon source and a lithium source, and performing heat treatment in a non-oxygen atmosphere to obtain a composite material containing Li.sub.2SiO.sub.3; and immersing the composite material containing Li.sub.2SiO.sub.3 in an acid solution to obtain the silicon-oxygen composite negative electrode material. The nano-silicon in the negative electrode material provided by the present application is wrapped by SiO.sub.x, and the surface of SiO.sub.x is further wrapped with the Li.sub.2SiO.sub.3 having a stable structure, making it difficult for the nano-silicon to come into physical contact with substances other than the SiO.sub.x and impossible to come into direct contact with water, thereby effectively inhibiting gas production of a battery.

The present application provides a silicon-oxygen composite negative electrode material and a preparation method therefor, and a lithium ion battery. The silicon-oxygen composite negative electrode material has a core-shell structure, the core comprises nano-silicon and a silicon oxide SiO.sub.x, and the shell comprises Li.sub.2SiO.sub.3. The preparation method comprises: mixing a silicon source and a lithium source, and performing heat treatment in a non-oxygen atmosphere to obtain a composite material containing Li.sub.2SiO.sub.3; and immersing the composite material containing Li.sub.2SiO.sub.3 in an acid solution to obtain the silicon-oxygen composite negative electrode material. The nano-silicon in the negative electrode material provided by the present application is wrapped by SiO.sub.x, and the surface of SiO.sub.x is further wrapped with the Li.sub.2SiO.sub.3 having a stable structure, making it difficult for the nano-silicon to come into physical contact with substances other than the SiO.sub.x and impossible to come into direct contact with water, thereby effectively inhibiting gas production of a battery.

An electrode and a method of manufacturing an electrode for a lithium secondary battery comprising a perforated current collector. The perforated current collector is capable of allowing active materials to be bonded through perforations of the perforated current collector, and at the same time, improving the energy density of the battery by reducing the weight even if the wet process and the electrically conductive material and binder, which are essential components of the existing electrode mixture, are excluded. The electrode for the lithium secondary battery comprises a first electrode active material layer; a second electrode active material layer; and a perforated current collector interposed between the first electrode active material layer and the second electrode active material layer and is characterized in that the first electrode active material layer and the second electrode active material layer are combined through perforations of the current collector.

An aspect of the present disclosure is a system that includes a first deposition system that includes a first cylinder having a first outer surface configured to hold a first substrate, a first spray nozzle configured to receive at least a first fluid, and a first fiber nozzle configured to receive at least a second fluid, where the first spray nozzle is configured to operate at a first voltage, the first fiber nozzle is configured to operate at a second voltage, the first cylinder is configured to be electrically connected to ground, the first spray nozzle is configured to apply onto the substrate a first plurality of at least one of particles or droplets from the first fluid, the first fiber nozzle is configured to apply onto the substrate a first fiber from the second fluid, and the first plurality of particles or droplets and the first fiber combine to form a first composite layer on the substrate.

Process for making a partially coated electrode active material wherein said process comprises the following steps: (a) Providing an electrode active material according to general formula Li.sub.1+xTM.sub.1-xO.sub.2, wherein TM is Ni and, optionally, at least one of Co and Mn, and, optionally, at least one element selected from Al, Mg, and Ba, transition metals other than Ni, Co, and Mn, and x is in the range of from zero to 0.2, wherein at least 50 mole-% of the transition metal of TM is Ni, (b) treating said electrode active material with an aqueous medium, (c) partially removing water by solid-liquid separation method, (d) treating the solid residue with an aqueous formulation of at least one heteropolyacid or its respective ammonium or lithium salt, (e) treating the residue thermally.

Provided are a negative electrode, which includes a current collector and a negative electrode active material layer disposed on the current collector, wherein the negative electrode active material layer includes a conductive material, a negative electrode active material, and a binder, the negative electrode active material includes a silicon-based active material having an elongation of from 0.05 to 0.35 and a circularity of from 0.9 to 0.98 as measured using a particle shape analyzer, and the elongation is defined by the following Formula 1, and a secondary battery including the negative electrode.

Elongation=1−Aspect ratio  [Formula 1]

Disclosed is a positive electrode for a lithium-sulfur battery, including a current collector; and a positive electrode active material layer on the current collector, wherein the positive electrode active material layer includes a positive electrode active material and a binder, and the positive electrode active material layer has surface properties defined by the following S.sub.a (arithmetic mean surface roughness of the positive electrode) and S.sub.z (maximum height roughness of the positive electrode) ((i) 1 μm≤S.sub.a≤5 μm, (ii) 10 μm≤S.sub.z≤60 μm (wherein S.sub.a is the average value of the distance from the middle surface of the surface irregularity structure of the positive electrode to the highest point and the lowest point of each irregularity part, and S.sub.z means the distance from the lowest point to the highest point of the positive electrode)) and a method for manufacturing the same.

Pre-lithiation methods using lithium vanadium fluorophosphate (e.g., LiVPO.sub.4F and its derivatives) (“LVPF”) as a cathode active material in a lithium-ion secondary battery. The pre-lithiation methods include compensating for an expected loss of active lithium by selecting LVPF having a specific pre-lithiated chemistry (or a blend of LVPF selected to have a specific pre-lithiated chemistry) and selecting a total amount of the pre-lithiated LVPF. The pre-lithiation methods may include initially charging the lithium-ion secondary battery at the lower of the two charge/discharge plateaus of LVPF to release active lithium.

Described is a lithium-sulfur electrochemical cell in which the anode and the cathode are each equipped with a respective solid-electrolyte interphase (SEI) layer that inhibits lithium side reactions. On the cathode side, the SEI layer inhibits the shuttle effect by retaining soluble polysulfides within a cathode active layer while releasing and admitting lithium ions to and from the electrolyte. The cathode SEI is deposited, during cell formation, by depositing a layer of an anode reductant (e.g., metallic lithium) on the surface of the cathode. The resultant electrically conductive layer allows electrons to reduce adjacent electrolyte and form the cathode SEI from electrolyte decomposition products.

Described is a lithium-sulfur electrochemical cell in which the anode and the cathode are each equipped with a respective solid-electrolyte interphase (SEI) layer that inhibits lithium side reactions. On the cathode side, the SEI layer inhibits the shuttle effect by retaining soluble polysulfides within a cathode active layer while releasing and admitting lithium ions to and from the electrolyte. The cathode SEI is deposited, during cell formation, by depositing a layer of an anode reductant (e.g., metallic lithium) on the surface of the cathode. The resultant electrically conductive layer allows electrons to reduce adjacent electrolyte and form the cathode SEI from electrolyte decomposition products.