Abstract:
Particles of cathodic materials are coated with polymer to prevent direct contact between the particles and the surrounding electrolyte. The polymers are held in place either by a) growing the polymers from initiators covalently bound to the particle, b) attachment of the already-formed polymers by covalently linking to functional groups attached to the particle, or c) electrostatic interactions resulting from incorporation of cationic or anionic groups in the polymer chain. Carbon or ceramic coatings may first be formed on the surfaces of the particles before the particles are coated with polymer. The polymer coating is both electronically and ionically conductive.
Abstract:
Polymer electrolytes incorporating PS-PEO block copolymers, PXE additives, and lithium salts provide improved physical properties relative to PS-PEO block copolymers and lithium salt alone, and thus provide improved battery performance.
Abstract:
A novel solid block copolymer electrolyte material is described. The material has first structural polymer blocks that make up a structural domain that has a modulus greater than 1 x 10 7 Pa at 25°C. There are also second ionically-conductive polymer blocks and a salt that make up an ionically-conductive domain adjacent to the structural domain. Along with the second ionically-conductive polymers, there is also a crosslinked network of third polymers, which interpenetrates the ionically-conductive domain. The third polymers are miscible with the second polymers. It has been shown that the addition of such an interpenetrating, crosslinked polymer network to the ionically-conductive domain improves the mechanical properties of the block copolymer electrolyte with no sacrifice in ionic conductivity.
Abstract:
Composites of lithium-ion-conducting ceramic and polymeric materials make superior separators and electrolytes for use in lithium batteries. The ceramic material provides a high conductivity pathway for lithium-ions, enhancing the properties of the less conductive polymeric material. The polymeric material provides flexibility, binding, and space-filling properties, mitigating the tendency of rigid ceramic materials to break or delaminate. The interface between the polymer and ceramic can be made to have a low ionic resistance through the use of additives and coatings.
Abstract:
In a solid-state lithium-metal/sulfur-based battery cell, barriers to sulfur and polysulfide diffusion are included in or used as an ionically conductive electrolyte in the cathode or separator layers. During operation of the battery, the barrier materials are positioned to either 1) rapidly react with any free sulfur or lithium polysulfide species that are generated, forming stable carbon-sulfur bond(s) and preventing further migration of the sulfur or polysulfide species or 2) prevent the formation and diffusion of elemental sulfur or free lithium polysulfide species. Regardless of the identity of the sulfur/polysulfide species, the sulfur-containing species is prevented from diffusing to the anode and causing capacity fade and higher internal resistance to ion flow.
Abstract:
This invention relates generally to electrolytes for use in electrochemical cells that employ alkali metals, and, more specifically, to fluorinated electrolytes for use in lithium-containing batteries. Perfluoropolyether electrolytes terminated with polar substituents such as cyclic carbonates show enhanced ionic conductivities when formulated with lithium bis(trifluoromethane)sulfonimide, making them useful for use as lithium cell electrolytes.
Abstract:
This invention relates generally to electrolytes for use in electrochemical cells that employ alkali metals, and, more specifically, to fluorinated electrolytes for use in lithium-containing batteries. Perfluoropolyether electrolytes terminated with polar substituents such as dimethylurethanes show enhanced ionic conductivities when formulated with lithium bis(trifluoromethane)sulfonimide, making them useful for use as lithium cell electrolytes.