摘要:
Improved cycling of high voltage lithium ion batteries is accomplished through the use of a formation step that seems to form a more stable structure for subsequent cycling and through the improved management of the charge-discharge cycling. In particular, the formation charge for the battery can be performed at a lower voltage prior to full activation of the battery through a charge to the specified operational voltage of the battery. With respect to management of the charging and discharging of the battery, it has been discovered that for the lithium rich high voltage compositions of interest that a deeper discharge can preserve the cycling capacity at a greater number of cycles. Battery management can be designed to exploit the improved cycling capacity obtained with deeper discharges of the battery.
摘要:
Supplemental lithium can be used to stabilize lithium ion batteries with lithium rich metal oxides as the positive electrode active material. Dramatic improvements in the specific capacity at long cycling have been obtained. The supplemental lithium can be provided with the negative electrode, or alternatively as a sacrificial material that is subsequently driven into the negative electrode active material. The supplemental lithium can be provided to the negative electrode active material prior to assembly of the battery using electrochemical deposition. The positive electrode active materials can comprise a layered-layered structure comprising manganese as well as nickel and/or cobalt.
摘要:
Improved cycling of high voltage lithium ion batteries is accomplished through the use of a formation step that seems to form a more stable structure for subsequent cycling and through the improved management of the charge-discharge cycling. In particular, the formation charge for the battery can be performed at a lower voltage prior to full activation of the battery through a charge to the specified operational voltage of the battery. With respect to management of the charging and discharging of the battery, it has been discovered that for the lithium rich high voltage compositions of interest that a deeper discharge can preserve the cycling capacity at a greater number of cycles. Battery management can be designed to exploit the improved cycling capacity obtained with deeper discharges of the battery.
摘要:
Lithium ion battery positive electrode material are described that comprise an active composition comprising lithium metal oxide coated with an inorganic coating composition wherein the coating composition comprises a metal chloride, metal bromide, metal iodide, or combinations thereof. Desirable performance is observed for these coated materials. In particular, the non-fluoride metal halide coatings are useful for stabilizing lithium rich metal oxides.
摘要:
Supplemental lithium can be used to stabilize lithium ion batteries with lithium rich metal oxides as the positive electrode active material. Dramatic improvements in the specific capacity at long cycling have been obtained. The supplemental lithium can be provided with the negative electrode, or alternatively as a sacrificial material that is subsequently driven into the negative electrode active material. The supplemental lithium can be provided to the negative electrode active material prior to assembly of the battery using electrochemical deposition. The positive electrode active materials can comprise a layered-layered structure comprising manganese as well as nickel and/or cobalt.
摘要:
Lithium ion battery positive electrode material are described that comprise an active composition comprising lithium metal oxide coated with an inorganic coating composition wherein the coating composition comprises a metal chloride, metal bromide, metal iodide, or combinations thereof. Desirable performance is observed for these coated materials. In particular, the non-fluoride metal halide coatings are useful for stabilizing lithium rich metal oxides.
摘要:
Batteries with particularly high energy capacity and low internal impedance have been described herein. The batteries can exhibit extraordinary long cycling with acceptable low amounts of fade. Pouch batteries using high specific capacity lithium rich metal oxide as positive electrode material combined with graphitic carbon anode can reach an energy density of at least about 180 Wh/kg at a rate of C/3 from 4.35V to 2V at room temperature while having a room temperature areas specific DC resistance of no more than about 75 ohms-cm2 at 20% SOC based on a full charge to 4.35V. High specific capacity lithium rich metal oxide with specific stoichiometry ranges used in these batteries are disclosed.
摘要:
Batteries with particularly high energy capacity and low internal impedance have been described herein. The batteries can exhibit extraordinary long cycling with acceptable low amounts of fade. Pouch batteries using high specific capacity lithium rich metal oxide as positive electrode material combined with graphitic carbon anode can reach an energy density of at least about 180 Wh/kg at a rate of C/3 from 4.35V to 2V at room temperature while having a room temperature areas specific DC resistance of no more than about 75 ohms-cm2 at 20% SOC based on a full charge to 4.35V. High specific capacity lithium rich metal oxide with specific stoichiometry ranges used in these batteries are disclosed.
摘要:
A porous silicon based material comprising porous crystalline elemental silicon formed by reducing silicon dioxide with a reducing metal in a heating process followed by acid etching is used to construct negative electrode used in lithium ion batteries. Gradual temperature heating ramp(s) with optional temperature steps can be used to perform the heating process. The porous silicon formed has a high surface area from about 10 m2/g to about 200 m2/g and is substantially free of carbon. The negative electrode formed can have a discharge specific capacity of at least 1800 mAh/g at rate of C/3 discharged from 1.5V to 0.005V against lithium with in some embodiments loading levels ranging from about 1.4 mg/cm2 to about 3.5 mg/cm2. In some embodiments, the porous silicon can be coated with a carbon coating or blended with carbon nanofibers or other conductive carbon material.
摘要:
High capacity silicon based anode active materials are described for lithium ion batteries. These materials are shown to be effective in combination with high capacity lithium rich cathode active materials. Supplemental lithium is shown to improve the cycling performance and reduce irreversible capacity loss for at least certain silicon based active materials. In particular silicon based active materials can be formed in composites with electrically conductive coatings, such as pyrolytic carbon coatings or metal coatings, and composites can also be formed with other electrically conductive carbon components, such as carbon nanofibers and carbon nanoparticles. Additional alloys with silicon are explored.