Abstract:
The present invention relates generally to electrochemical energy storage devices such as Li-ion batteries, and more particularly to a method of providing uniform ceramic coatings with controlled thicknesses for separators in such storage devices. Some embodiments of the invention utilize a layer by layer coating of nano/micro-sized particles dispersed in a solvent, which can be aqueous or non-aqueous. Other embodiments of the invention utilize a dry process such as PVD for depositing a ceramic film on a porous polyolefin separator. According to certain aspects of the invention, advantages of this approach include the ability to achieve a denser more uniform film with better controlled thickness with less waste and higher yield than current ceramic coating technology. An advantage of a ceramic coated separator is increased safety of cells.
Abstract:
The present invention generally relates to using water-based binders for high voltage cathode materials, such as LMNO (spinel LiNi0.5Mn1.5O4), in Li-ion batteries. An example of a water compatible polymer binder according to some embodiments of the present invention is a combination of CMC (carboxymethylcellulose) and a second water compatible polymer that produce coatings of adequate thickness and loading (mAh/cm2). A method of forming a cathode for a Li-ion battery may include: preparing an aqueous solution of CMC; mixing together LMNO and carbon black; combining the LMNO and carbon black mixture with the CMC solution, an aqueous polyacrylic solution and distilled water, and mixing to form a slurry; coating a conductive substrate with the slurry; and drying the coated substrate, forming a cathode layer on the substrate. Furthermore, this invention describes a cathode for Li-ion batteries and tools for carrying out the above method.
Abstract:
A method and apparatus for forming battery active material on a substrate are disclosed. In one embodiment, an apparatus for depositing a battery active material on a surface of a substrate includes a substrate conveyor system for transporting the substrate within the apparatus, a material spray assembly disposed above the substrate conveyor system, and a first heating element disposed adjacent to the material spray assembly above the substrate conveyor system configured to heat the substrate. The material spray assembly has a 2-D array of nozzles configured to electrospray an electrode forming solution on the surface of the substrate.
Abstract:
The present invention relates generally to electrochemical energy storage devices such as Li-ion batteries, and more particularly to a method of providing uniform ceramic coatings with controlled thicknesses for separators in such storage devices. Some embodiments of the invention utilize a layer by layer coating of nano/micro-sized particles dispersed in a solvent, which can be aqueous or non-aqueous. Other embodiments of the invention utilize a dry process such as PVD for depositing a ceramic film on a porous polyolefin separator. According to certain aspects of the invention, advantages of this approach include the ability to achieve a denser more uniform film with better controlled thickness with less waste and higher yield than current ceramic coating technology. An advantage of a ceramic coated separator is increased safety of cells.