The present invention relates to a negative electrode for a lithium secondary battery and a lithium secondary battery comprising the same. The negative electrode for a lithium secondary battery comprises a current collector and a negative electrode active material layer formed on the current collector, wherein the negative electrode active material layer includes a first negative electrode active material and a first binder, and a second active material layer formed on the first active material layer and including a second negative electrode active material and a second binder, a content of the first binder is greater than that of the second binder, a loading level of the negative electrode active material layer is 10 mg/cm.sup.2 to 30 mg/cm.sup.2, a loading level of the first active material layer is 4 mg/cm.sup.2 to 25 mg/cm.sup.2, a loading level of the second active material layer is 4 mg/cm.sup.2 to 25 mg/cm.sup.2, and a loading level of the second active material layer is equal to or higher than that of the first active material layer.

A method for processing a negative electrode plate, a sodium-metal negative electrode plate and related devices. In a vacuum environment, the metal vapor reacts with oxygen, and the metal oxide formed by the reaction is plated on the surface of the sodium-metal negative electrode plate to form a metal oxide protective layer with high mechanical strength and stable chemical properties. The metal oxide protective layer can greatly reduce the phenomenon of low yield and performance deterioration caused by the reaction of sodium metal with air and water during the processing of the sodium-metal negative electrode plate. Since the metal oxide has a nanoscale thickness, it can form a corresponding sodium salt with sodium metal under electrochemical conditions, thereby improving the sodium ion transport rate on the surface of the sodium-metal negative electrode plate and improving the battery’s kinetic performance.

A method for processing a negative electrode plate, a sodium-metal negative electrode plate and related devices. In a vacuum environment, the metal vapor reacts with oxygen, and the metal oxide formed by the reaction is plated on the surface of the sodium-metal negative electrode plate to form a metal oxide protective layer with high mechanical strength and stable chemical properties. The metal oxide protective layer can greatly reduce the phenomenon of low yield and performance deterioration caused by the reaction of sodium metal with air and water during the processing of the sodium-metal negative electrode plate. Since the metal oxide has a nanoscale thickness, it can form a corresponding sodium salt with sodium metal under electrochemical conditions, thereby improving the sodium ion transport rate on the surface of the sodium-metal negative electrode plate and improving the battery’s kinetic performance.

A composite negative electrode based on pure metallic lithium, pure metallic sodium or one of their alloys and a polymer membrane, a method for manufacturing such an electrode, as well as an electrical energy storage system, in particular an electrochemical accumulator such as a secondary (rechargeable) lithium or sodium battery comprising at least one such negative electrode. It is particularly applicable to Lithium-Metal-Polymer or LMP™ batteries.

Various implementations of a method of forming an electrochemical cell include providing a first electrode, a second electrode, a separator between the first and second electrodes, and an electrolyte in a cell container. The first electrode can include silicon-dominant electrochemically active material. The silicon-dominant electrochemically active material can include greater than 50% silicon by weight. The method can also include exposing at least a part of the electrochemical cell to CO.sub.2, and forming a solid electrolyte interphase (SEI) layer on the first electrode using the CO.sub.2.

Various implementations of a method of forming an electrochemical cell include providing a first electrode, a second electrode, a separator between the first and second electrodes, and an electrolyte in a cell container. The first electrode can include silicon-dominant electrochemically active material. The silicon-dominant electrochemically active material can include greater than 50% silicon by weight. The method can also include exposing at least a part of the electrochemical cell to CO.sub.2, and forming a solid electrolyte interphase (SEI) layer on the first electrode using the CO.sub.2.

A negative electrode for a lithium secondary battery, a lithium secondary battery including the negative electrode, and a method for manufacturing the lithium secondary battery, where the negative electrode includes a negative electrode current collector; and a negative electrode active material layer on at least one surface of the negative electrode current collector. The negative electrode active material layer includes a Si-containing negative electrode active material, a conductive material and a first binder polymer. The Si-containing negative electrode active material has cracks formed after activation, and a second binder polymer is present in the cracks. The first binder polymer and the second binder polymer are heterogeneous (e.g., different from each other). The lithium secondary battery shows improved life characteristics.

A non-aqueous electrolyte secondary battery according to an aspect of the present disclosure is provided with a negative electrode having: a negative electrode collector: a first negative electrode mixture layer provided on the surface of the negative electrode collector; and a second negative electrode mixture layer provided on the surface of the first negative electrode mixture layer. Each of the first negative electrode mixture layer and the second negative electrode mixture layer contains graphite particles. The ratio (S2/S1) of the inter-particle porosity (S2) of the graphite particles in the second negative electrode mixture layer to the inter-particle porosity (S1) of the graphite particles in the first negative electrode mixture layer is 1.1-2.0. The ratio (D2/D1) of the filling density (D2) of the second negative electrode mixture layer to the filling density (D1) of the first negative electrode mixture layer is 0.9-1.1.

Method for pre-lithiating an anode, wherein the method comprises the steps of: packing an anode sheet with a lithium-comprising sheet as a jelly roll or stack in an electrolyte; transferring lithium ions to the anode sheet to obtain a pre-lithiated anode sheet by direct contact between the anode sheet and the lithium-comprising sheet or by discharging or charging the anode sheet towards the lithium-comprising sheet; and dividing the pre-lithiated anode sheet into a plurality of pre-lithiated anodes of a desired size and shape. The invention further relates to an electrochemical cell comprising an an-ode which is pre-lithiated by the method.

Disclosed is a method of fabricating an anode for a lithium-ion battery, including milling a mixture of nano-silicon, one or more carbonaceous materials and one or more solvents, wherein the mixture is retained as a wet slurry during milling. The mixture is carbonised to produce a silicon thinly coated with carbon (Si@C) material. Further milling occurs of a second mixture of the Si@C material, one or more graphite, one or more second carbonaceous materials and one or more second solvents, wherein the second mixture is retained as a second wet slurry during milling. The second mixture is carbonised to produce a Si@C/graphite/carbon material. The anode is formed from the Si@C/graphite/carbon material.