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: Syntheses of alternating copolymers based on PEO and fluorinated polymers are described. Introduction of fluorinated polymer chains reduces the Tm of PEO and also increases the affinity and miscibility with ionic liquids, which improves ionic conductivity even at room temperature. The disclosed polymers containing PFPE have superior safety and are more flame retardant as compared to traditional electrolytes. Such alternating copolymers can be used as solid or gel electrolytes in Li batteries.

Abstract: A polymer to be used as a binder for sulfur-based cathodes in lithium batteries that includes in its composition electrophilic groups capable of reaction with and entrapment of polysulfide species. Beneficial effects include reductions in capacity loss and ionic resistance gain.

Abstract: A polymer to be used as a binder for sulfur-based cathodes in lithium batteries that includes in its composition electrophilic groups capable of reaction with and entrapment of polysulfide species. Beneficial effects include reductions in capacity loss and ionic resistance gain.

Abstract: Syntheses of graft copolymers based on PEO and fluorinated functional groups are described. Grafting of fluorinated groups reduces the Tm of PEO and also increases the miscibility of PEO with ionic liquids, so that addition of ionic liquids improves ionic conductivity even at room temperature. The disclosed copolymers containing fluorinated functionality have superior safety and are more flame retardant as compared to traditional electrolytes. Such copolymers can be used as either solid or gel electrolytes in Li batteries.

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: New polymer compositions based on poly(2,6-dimethyl-1,4-phenylene oxide) and other high-softening-temperature polymers are disclosed. These materials have a microphase domain structure that has an ionically-conductive phase and a phase with good mechanical strength and a high softening temperature. In one arrangement, the structural block has a softening temperature of about 210° C. These materials can be made with either homopolymers or with block copolymers.

Abstract: A class of polymeric phosphorous esters can be used as binders for battery cathodes. Metal salts can be added to the polymers to provide ionic conductivity. The polymeric phosphorous esters can be formulated with other polymers either as mixtures or as copolymers to provide additional desirable properties. Examples of such properties include even higher ionic conductivity and improved mechanical properties. Furthermore, cathodes that include the polymeric phosphorous esters can be assembled with a polymeric electrolyte separator and an anode to form a complete battery.

Abstract: A novel anode for a lithium battery cell is provided. The anode contains silicon nanoparticles embedded in a solid polymer electrolyte. The electrolyte can also act as a binder for the silicon nanoparticles. A plurality of voids is dispersed throughout the solid polymer electrolyte. The anode may also contain electronically conductive carbon particles. Upon charging of the cell, the silicon nanoparticles expand as take up lithium ions. The solid polymer electrolyte can deform reversibly in response to the expansion of the nanoparticles and transfer the volume expansion to the voids.

Abstract: The accurate determination of the state-of-charge (SOC) of batteries is an important element of battery management. One method to determine SOC is to measure the voltage of the cell and exploiting the correlation between voltage and SOC. For electrodes with sloped charge/discharge profiles, this is a good method. However, for batteries with lithium iron phosphate (LFP) cathodes the charge/discharge profile is flat. Now, by using the materials and methods disclosed herein, an amount of cathode active material that has a sloped charge/discharge profile is mixed with LFP in a cathode, which results in a charge/discharge profile with enough slope that the SOC of the battery can be determined by measuring the voltage alone.

Abstract: The isolation resistance value is determined by measuring the voltage across a set of high resistance resistor networks placed between the high voltage battery pack (both the positive and negative terminals) and the chassis ground and then modifying the resistance networks by switching in an additional high resistance network and repeating the measurements. This results in a system that can be assembled using low cost components to determine with a high degree of accuracy the value of the isolation resistance. The implementation of this system does not require expensive solid state relays, as the small amount of resistance through the switching device is negligible when determining the isolation resistance of the high voltage system. The system is not dependent on high precision devices to give accurate isolation resistance detection in a range that is appropriate for high voltage applications.

Abstract: Perfluoropolyether electrolytes terminated with polar substituents such as dimethylurethanes show enhanced ionic conductivities when formulated with lithium bis(trifluoromethane)sulfonimide, making them useful as electrolytes for lithium cells.

Abstract: Perfluoropolyether electrolytes terminated with polar substituents such as cyclic carbonates show enhanced ionic conductivities when formulated with lithium bis(trifluoromethane)sulfonimide, making them useful as electrolytes for lithium cells.

Abstract: A sulfur-based cathode for use in an electrochemical cell is disclosed. The sulfur is sequestered to the cathode to enhance cycle lifetime for the cathode and the cell. An exemplary sulfur-based cathode is coupled with a solid polymer electrolyte instead of a conventional liquid electrolyte. The dry, solid polymer electrolyte further acts as a diffusion barrier for the sulfur. Together with a sequestering matrix in the cathode, the solid polymer electrolyte prevents sulfur capacity fade that occurs in conventional liquid electrolyte based sulfur systems. The sequestering polymer in the cathode further binds the sulfur-containing active particles, preventing sulfur agglomerates from forming, while still allowing lithium ions to be transported between the anode and cathode.

Abstract: A polymer to be used as a binder for sulfur-based cathodes in lithium batteries that includes in its composition electrophilic groups capable of reaction with and entrapment of polysulfide species. Beneficial effects include reductions in capacity loss and ionic resistance gain.

Abstract: An optimal architecture for a polymer electrolyte battery, wherein one or more layers of electrolyte (e.g., solid block-copolymer) are situated between two electrodes, is disclosed. An anolyte layer, adjacent the anode, is chosen to be chemically and electrochemically stable against the anode active material. A catholyte layer, adjacent the cathode, is chosen to be chemically and electrochemically stable against the cathode active material.

Abstract: Perfluoropolyether electrolytes have either one or two terminal nitrile groups and an alkali metal salt. The alkali metal salt can be a lithium salt, a sodium salt, a potassium salt, or a cesium salt. The salt can make up between 5 and 30 wt % of the electrolyte composition. Such electrolytes have shown high ionic conductivities, making them useful as lithium cell electrolytes.

Abstract: Electrode assemblies for use in electrochemical cells are provided. The negative electrode assembly includes negative electrode active material and an electrolyte chosen specifically for its useful properties in the negative electrode. Such properties include reductive stability and ability to accommodate expansion and contraction of the negative electrode active material. Similarly, the positive electrode assembly includes positive electrode active material and an electrolyte chosen specifically for its useful properties in the positive electrode. These properties include oxidative stability and the ability to prevent dissolution of transition metals used in the positive electrode active material. A third electrolyte can be used as separator between the negative electrode and the positive electrode. A cell is constructed with a cathode that includes a fluorinated electrolyte which does not penetrate into the solid-state polymer electrolyte separator between it and the lithium-based anode.

Abstract: A novel electrode for a battery is provided. The electrode may contain active material nanoparticles embedded in a solid polymer electrolyte. The electrolyte can also act as a binder for the nanoparticles. A plurality of voids is dispersed throughout the solid polymer electrolyte. The electrode may also contain electronically conductive carbon particles. Upon charging or discharging of the cell, the nanoparticles expand as they take up active material ions. The solid polymer electrolyte can deform reversibly in response to the expansion of the nanoparticles and transfer the volume expansion to the voids.

Abstract: A polymer to be used as a binder for sulfur-based cathodes in lithium batteries that includes in its composition electrophilic groups capable of reaction with and entrapment of polysulfide species. Beneficial effects include reductions in capacity loss and ionic resistance gain.