Surface and bulk modified high capacity layered oxide cathodes with low irreversible capacity loss

The present invention includes compositions, surface and bulk modifications, and methods of making of (1-x)Li[Li.sub.1/3Mn.sub.2/3]O.sub.2.xLi[Mn.sub.0.5-yNi.sub.0.5-yCo.sub.2- y]O.sub.2 cathode materials having an O3 crystal structure with a x value between 0 and 1 and y value between 0 and 0.5, reducing the irreversible capacity loss in the first cycle by surface modification with oxides and bulk modification with cationic and anionic substitutions, and increasing the reversible capacity to close to the theoretical value of insertion/extraction of one lithium per transition metal ion (250-300 mAh/g)

Surface and bulk modified high capacity layered oxide cathodes with low irreversible capacity loss

The present invention includes compositions, surface and bulk modifications, and methods of making of (1−x)Li[Li1/3Mn2/3]O2.xLi[Mn0.5-yNi0.5-yCo2y]O2 cathode materials having an O3 crystal structure with a x value between 0 and 1 and y value between 0 and 0.5, reducing the irreversible capacity loss in the first cycle by surface modification with oxides and bulk modification with cationic and anionic substitutions, and increasing the reversible capacity to close to the theoretical value of insertion/extraction of one lithium per transition metal ion (250-300 mAh/g).Board of Regents, University of Texas Syste

Elucidating the electrochemical activity of electrolyte-insoluble polysulfide species in lithium-sulfur batteries

The direct synthesis of Li2 S2 , a proposed solid intermediate in the discharge of lithium-sulfur (Li-S) batteries, was accomplished by treating elemental lithium with sulfur in liquid ammonia at -41?? C. The as-synthesized product was analyzed by X-ray photoelectron spectroscopy (XPS) as well as X-ray diffraction (XRD) and determined to be a mixture of crystalline Li2 S, amorphous Li2 S2, and higher-order polysulfides (Li2 Sx , x > 2). Monitored filtration followed by a tailored electrochemical approach was used to successfully remove the higher-order polysulfides and yielded a powder, which was determined by XPS to be comprised of 9 mol% insoluble polysulfide species (mainly Li2 S2 ) and 91 mol% Li2 S. This material was discharged galvanostatically in an electrochemical cell and, despite the lack of soluble polysulfide species, was shown to exhibit a discharge plateau at 2.1 V vs. Li/Li+ . This result confirmed the electrochemical reducibility of electrolyte-insoluble polysulfides in Li-S batteries. Moreover, it was determined that the reduction of solid polysulfides was confined to areas where the sulfur-sulfur bonds were in intimate contact with the conductive current collector. Finally, it was observed that commercially available Li2 S samples contain significant quantities of polysulfide-type impurities.ope

A Bifunctional Hybrid Electrocatalyst for Oxygen Reduction and Oxygen Evolution Reactions: Nano-Co3O4-Deposited La0.5Sr0.5MnO3 via Infiltration

For rechargeable metal-air batteries, which are a promising energy storage device for renewable and sustainable energy technologies, the development of cost-effective electrocatalysts with effective bifunctional activity for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) has been a challenging task. To realize highly effective ORR and OER electrocatalysts, we present a hybrid catalyst, Co3O4-infiltrated La0.5Sr0.5MnO3-delta (LSM@Co3O4), synthesized using an electrospray and infiltration technique. This study expands the scope of the infiltration technique by depositing similar to 18 nm nanoparticles on unprecedented similar to 70 nm nano-scaffolds. The hybrid LSM@Co3O4 catalyst exhibits high catalytic activities for both ORR and OER (similar to 7 times, similar to 1.5 times, and similar to 1.6 times higher than LSM, Co3O4, and IrO2, respectively) in terms of onset potential and limiting current density. Moreover, with the LSM@Co3O4, the number of electrons transferred reaches four, indicating that the catalyst is effective in the reduction reaction of O-2 via a direct four-electron pathway. The study demonstrates that hybrid catalysts are a promising approach for oxygen electrocatalysts for renewable and sustainable energy devices

High-Performance Heterostructured Cathodes for Lithium-Ion Batteries with a Ni-Rich Layered Oxide Core and a Li-Rich Layered Oxide Shell

The Ni-rich layered oxides with a Ni content of >0.5 are drawing much attention recently to increase the energy density of lithium-ion batteries. However, the Ni-rich layered oxides suffer from aggressive reaction of the cathode surface with the organic electrolyte at the higher operating voltages, resulting in consequent impedance rise and capacity fade. To overcome this difficulty, we present here a heterostructure composed of a Ni-rich LiNi0.7Co0.15Mn0.15O2 core and a Li-rich Li1.2-xNi0.2Mn0.6O2 shell, incorporating the advantageous features of the structural stability of the core and chemical stability of the shell. With a unique chemical treatment for the activation of the Li2MnO3 phase of the shell, a high capacity is realized with the Li-rich shell material. Aberration-corrected scanning transmission electron microscopy (STEM) provides direct evidence for the formation of surface Li-rich shell layer. As a result, the heterostructure exhibits a high capacity retention of 98% and a discharge- voltage retention of 97% during 100 cycles with a discharge capacity of 190 mA h g(-1) (at 2.0-4.5 V under C/3 rate, 1C = 200 mA g(-1)).ope

High energy density aluminum battery

Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.Board of Regents, University of Texas Syste

Recent progress on nanostructured 4 v cathode materials for Li-ion batteries for mobile electronics

Mobile electronics have developed so rapidly that battery technology has hardly been able to keep pace. The increasing desire for lighter and thinner Li-ion batteries with higher capacities is a continuing and constant goal for in research. Achieving higher energy densities, which is mainly dependent on cathode materials, has become a critical issue in the development of new Li-ion batteries. In this review, we will outline the progress on nanostructured 4 V cathode materials of Li-ion batteries for mobile electronics, covering LiCoO2, LiNixCoyMn1-x-yO 2, LiMn2O4, LiNi0.5Mn 1.5O4 and Li-rich layered oxide materials. We aim to provide some scientific insights into the development of superior cathode materials by discussing the advantages of nanostructure, surface-coating, and other key properties.open2