Improving Cycling Performance of EV Batteries

Lithium secondary battery with improved performance by using a specific ratio of charge/discharge capacity for the positive electrode additive during initial charging. The additive, represented by formula 1, is an irreversible compound that reduces lithium ion loss during charging. By adjusting the charge/discharge capacity ratio of the additive to 50-100% during initial charging, it reduces oxygen gas generation, prevents self-discharging, and improves open circuit voltage. This improves battery performance compared to conventional additives with higher oxygen gas generation.

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Lithium ion battery with improved safety, high-temperature performance, and energy density. The battery contains a positive electrode with a lithium-rich metal oxide like Li2NiO2 and a fluorine level in the electrolyte lithium salt below 14%. This reduces lithium loss, electrolyte decomposition, and metal ion dissolution, improving safety and high-temp cycling/storage. The lithium-rich oxide provides supplemental lithium, while the lower fluorine electrolyte reduces side reactions.

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Lithium-rich secondary battery with improved capacity, stability, and lifespan by modifying the surface of the positive electrode active material. The modification involves treating the lithium manganese nickel oxide (LMNO) positive electrode material with a sulfur precursor like thiourea to create a sulfate coating on the surface. The resulting battery has reduced oxygen irreversible extraction during charging/discharging, preventing structure collapse and voltage drop. The sulfur content in the modified electrode is 0.3-1.0% by weight.

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Method for pre-lithiating a negative electrode of a lithium secondary battery by over-lithiating a positive electrode with manganese-based oxide and then transferring lithium from the over-lithiated positive electrode to the negative electrode. The method involves charging the positive electrode at a low voltage to stabilize the manganese phase, resting, and then charging at a higher voltage to transfer lithium to the negative electrode. This improves negative electrode efficiency and lifetime by compensating irreversible capacity.

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Electrolyte for lithium metal batteries that improves lifespan and performance compared to conventional electrolytes. The electrolyte contains a lithium salt (like lithium bis(fluorosulfonyl)imide) at a concentration of 2.0-4.0 M, along with specific solvents. These are 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether (OTE) as a non-aqueous solvent, cyclic fluorinated carbonate (like fluoroethylene carbonate), and chain solvents like dimethyl carbonate. The OTE concentration is 32% or less of the total solvent volume. This electrolyte composition provides better stability and longevity when used in lithium metal batteries compared

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A lithium-ion battery design that reduces degradation during cycling by preventing reaction between lithium metal deposited on the negative electrode and the electrolyte. The battery uses a specific solvent, vinylene carbonate, in the electrolyte solution. Lithium metal precipitates on the negative electrode during charging, and during discharging, it dissolves back into the electrolyte. The vinylene carbonate solvent prevents direct contact between the lithium metal and the electrolyte, avoiding electrolyte decomposition and reaction with the lithium. This improves cycle life compared to batteries with other solvents. The battery also has a negative electrode current collector that doesn't alloy with lithium to further prevent electrolyte reactions.

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Charging and discharging method for lithium ion batteries with high capacity retention rate, especially for batteries with additional third and fourth electrodes. The method involves selective lithium supplementation and controlled discharge of the third and fourth electrodes. When the battery capacity attenuates, the third and fourth electrodes are charged to replenish lithium. This prevents irreversible capacity loss. The discharge capacity of the third and fourth electrodes is calculated based on current and time to avoid excessive lithium precipitation. The method allows targeted lithium release based on cell needs and prevents dendrites.

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Lithium ion battery control to minimize deterioration by optimizing charging and discharging based on lithium ion occlusion. The control involves monitoring a degree of lithium ion occlusion in the battery's graphite negative electrode, which changes with charge/discharge, and adjusting charging/discharging to keep occlusion close to a specific region associated with lower degradation. This prevents excessive occlusion in regions prone to high occlusion. By targeting the region with lower occlusion, it reduces overall battery degradation compared to conventional methods.

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Electrolyte composition for high voltage lithium-ion batteries that improves cycling stability of high capacity positive electrodes containing lithium-rich metal oxides. The electrolyte contains specific additives like dimethyl methylphosphonate, lithium boron compounds, thiophene derivatives, lithium fluoride, and anion complexing agents. These additives stabilize the positive electrode during cycling by mechanisms like complexing reactive species, polymerizing on the electrode, and shifting equilibria. The additives are combined with carbonate-based solvents like ethylene carbonate, dimethyl carbonate, and methyl ethyl carbonate.

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High voltage lithium-ion batteries with improved stability and cycling performance at elevated voltages above 4.35V. The batteries contain a cathode with doped lithium cobalt oxide (LiCoO2) particles and an electrolyte with succinonitrile (SN) and lithium bis(oxalato)borate (LiBOB) additives. The doped LiCoO2 cathode allows stable charging above 4.35V due to optimized phase transitions. The SN and LiBOB electrolyte additives reduce impedance buildup during high voltage storage. This allows the batteries to store and cycle at high voltages without degradation.

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Process to reduce degassing and self-discharge in lithium-ion batteries with spinel cathodes like LiNixMn2-xO4 (LNMO) with 0<x≤0.5. The process involves a specific formation cycle for the battery. It includes charging the battery to full capacity, discharging it to 10-0% state of charge, then storing it for a week at 15-45°C. This cycle improves stability and reduces degassing/self-discharge of the LNMO cathode compared to standard battery formation. The process can also involve charging to 10-20% instead of full capacity.

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High energy density, high power lithium metal rechargeable batteries with volumetric energy density >1000 Wh/L and gravimetric energy density >350 Wh/kg, capable of discharging >1 C at room temperature. The batteries have thin lithium metal anodes (<20 µm), low capacity cathodes (n/p < 1), thin separators (<12 µm), and electrolytes with high salt concentration (>2 M Li) to suppress dendrite growth. The thin anode allows high capacity cathodes without excess lithium. The separator isolates dendrites from the cathode. The high salt electrolyte improves cycling.

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Formation process for lithium-ion batteries that prelithiates the anode during initial charging cycles to mitigate volume changes and improve cycling life. The process involves charging the battery to a higher voltage than normal in the first cycle to extract lithium from the cathode. This lithium is stored in the anode instead of plating on it. Subsequent cycles maintain the higher cutoff voltage to keep the anode prelithiated. This reduces irreversible capacity loss and anode volume changes compared to charging to the normal cutoff voltage.

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Protecting lithium-ion batteries from over-discharge damage by using a cathode material that has irreversible capacity loss during charging and a voltage step below 2V versus lithium. This cathode provides over-discharge protection by preventing copper current collector dissolution during over-discharge because the anode voltage remains below the copper dissolution potential. The cathode composition is xLi2MnO3.(1−x)LiMnaNibCocO2 with x=0.41 to 0.59. The specific composition and ratio of Mn, Ni, Co, and Li can be selected to achieve the desired irreversible capacity loss and voltage plateau.

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A lithium-ion battery system with improved input power and energy density by balancing the capacity ratio of the cathode and anode. The system uses a lithium-ion battery with a manganese-nickel oxide cathode and a lithium-titanium oxide anode. The anode-to-cathode capacity ratio is 0.7 or more and less than 1. This optimizes energy density and prevents excessive cathode potential to suppress electrolyte degradation. The end-of-charge voltage is regulated between 3.6 and 4.0V.

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Lithium-ion battery with improved cycle life and reduced swelling by using a specific electrolyte composition. The battery has a silicon oxide anode, lithium cobalt oxide cathode, and an electrolyte containing LiPF6 salt, EC:DEC solvent (1:2 ratio), and 8-12% FEC additive. This electrolyte reduces swelling and improves cycle life compared to standard electrolytes. The silicon oxide anode helps retain lithium, prevent dendrites, and expand less compared to pure lithium anodes.

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Lithium-ion battery with improved initial capacity and cycle life for applications like electric vehicles. The battery uses a specific electrolyte and voltage range when charging and discharging. The electrolyte contains dimethyl carbonate (DMC) and the charging voltage is 3.4-3.8 V. The discharging voltage is 2.0-2.8 V. This combination helps prevent electrolyte decomposition and manganese expansion during charging, while avoiding lithium plating and manganese reduction during discharging.

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Electrolyte for lithium metal batteries that allows stable cycling of lithium metal anodes without dendrite growth, SEI film formation, and short circuits. The electrolyte contains specific salt compositions like LiFSI, LiBOB, LiPF6, solvents EC/DMC, and additives FEC/VC in optimized ranges. The electrolyte provides a thin, rigid, and stable SEI on the lithium anode surface that prevents dendrite growth and SEI thickening. It also inhibits side reactions with the electrolyte and improves lithium metal battery cycling life.

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Battery pack design and charge/discharge control to improve cycle life of lithium batteries with silicon-containing negative electrodes. The pack has a predetermined cutoff voltage during discharge to prevent excessive lithium deintercalation from the silicon that can cause cracks. This prevents capacity fade and cycle degradation by avoiding the strain-induced cracking in the amorphous lithium-silicon phase that forms during charge/discharge cycling. The cutoff voltage is set to limit lithium concentration in the silicon below a threshold that avoids cracking during discharge.

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