52 results about "Decomposition potential" patented technology

Provided in the present invention are a rare earth metal and a rare earth metal alloy and a method for the preparation of these by molten salt electrolysis. In the method for the preparation of the rare earth metal alloy by molten salt electrolysis, the electrolyte is an alkali metal or the chloride-fused salt of an alkaline earth metal, the positive electrode is an inert electrode or graphite, the negative electrode is composed of a rare-earth metal oxide and the oxides of other alloy components and/or metal powders, and electrolysis is induced by the passage of a direct current. During the electrolytic process, the temperature of electrolysis is higher than the melting point of the rare earth metal alloy produced and lower than the melting point of the negative electrode; the surface layer of the positive electrode is in the first stage electrolyzed to a liquid metal film which accumulates to a certain volume before falling to the crucible at the bottom. The current density of the negative electrode is sufficient to separate out from said negative electrode the components of the rare earth metal alloy. The electrolysis voltage is lower than the decomposition potential of the electrolyte and higher than the decomposition potential of the oxides corresponding to each component of the rare earth metal alloy. A crucible is used to collect the rare earth metal and the alloy obtained through the present method. The present method is technically simple and environmentally-friendly, while featuring low energy consumption, high current efficiency, and low costs.

The invention relates to an electrolyte adopting propylene carbonate as a main solvent, which relates to the electrolyte of a lithium ion battery. The electrolyte contains lithium salt, organic solvent and additive; the organic solvent contains propylene carbonate and chain-type carbonic ester; the additive contains a film-forming additive A and an additive B for inhibiting the embedding of the propylene carbonate; the electrolyte contains the following components by mass percent: 10 to 18 percent of lithium salt, 25 to 60 percent of propylene carbonate, 15 to 60 percent of chain-type carbonic ester, 0.5 to 5 percent of additive A and 0.1 to 10 percent of the additive B. Sulfite is used as the additive of the lithium ion battery electrolyte; since the sulfite is high in reduction potential which is higher than the decomposition potential of the propylene carbonate, the sulfite forms a layer of stable and compact SEI film on the surface of graphite before the decomposition of the propylene carbonate, the propylene carbonate solvent can be effectively prevented from being collectively embedded into the graphite layer along with the lithium ion, the initial discharging capacity of the battery is improved, and the cycle life of the battery is prolonged.

A lithium-ion battery includes a positive electrode comprising a current collector and a first active material and a negative electrode comprising a current collector, a second active material, and a third active material. The second active material comprises a lithium titanate material and the third active material is selected from the group consisting of Li_xVO₂ where x is between 0.05 and 0.4, LiM_xMn_(2−x)O₄ where M is a metal and x is less than or equal to 1, V₆O₁₃, V₂O₅, V₃O₈, MoO₃, TiS₂, WO₂, MoO₂, RuO₂, and combinations thereof. The third active material exhibits charging and discharging capacity below a corrosion potential of the current collector of the negative electrode and above a decomposition potential of the first active material.

The invention belongs to the field of lithium ion battery electrolyte technology, and provides high voltage electrolyte for a lithium ion battery. The high voltage electrolyte comprises lithium salt, an organic solvent and an additive; and the high voltage electrolyte is characterized in that the organic solvent comprises fluoroester and a common carbonic ester organic solvent, wherein the organic solvent comprises 5-30% of the fluoroester by mass; the additive comprises ionic liquid and an film forming additive, and the mass percentage content is 0.01-8%. The high voltage electrolyte can enhance oxidative decomposition potential of the electrolyte, prolong cycle life of the lithium ion battery, and solve gas expansion and other problems of the lithium ion battery.

The invention discloses a silicon-containing organic compound and application thereof. The silicon-containing organosilicon compound mainly comprises organic silicon carbonates, organic silicon carboxylates and ether modified silanes. The silicon-containing organic compound can be applied to lithium ion battery electrolyte, and serves as a solvent for the lithium ion battery electrolyte, the lithium ion battery electrolyte further comprises ethylene carbonate, propylene carbonate, methyl ethyl carbonate and diethyl carbonate which are used as basic solvents as well as lithium hexafluorophosphate, vinylene carbonate, 1,3-propanesulfonate and fluoroethylene carbonate which are taken as additives. The organosilicon compound electrolyte solvent has high oxidative decomposition potential, hightemperature resistance and high voltage resisting stability of a lithium ion battery can be improved quite well, wettability and low viscosity are good, the lithium ion conductivity can be improved quite well, the rate capability and the safety of the battery are improved, and the silicon-containing organic compound is a novel second-generation lithium ion battery solvent.

An aspect of the invention resides in a nonaqueous electrolyte secondary battery (10) including a positive electrode (11), a negative electrode (12) and a nonaqueous electrolytic solution, the positive electrode including a positive electrode active material containing a lithium transition metal oxide having a rare earth compound attached on the surface, the nonaqueous electrolytic solution including an aromatic compound having an oxidative decomposition potential in the range of 4.2 to 5.0 V vs. Li/Li⁺. The rare earth compound is preferably a rare earth hydroxide, a rare earth oxyhydroxide or a rare earth oxide.

The invention relates to a composite cathode material and a preparation method thereof and a lithium ion battery, and belongs to the technical field of batteries. The composite cathode material comprises a cathode material, a metal compound layer and a lithium peroxide layer, the surface of the cathode material is coated with the metal compound layer, and the surface of the side, away from the cathode material, of the metal compound layer is coated with the lithium peroxide layer. The metal compound layer of the composite cathode material can be used as a catalyst to reduce the decomposition potential of lithium peroxide, and in the first charging process, the metal compound can catalyze efficient decomposition of lithium peroxide and release Li+ for efficient lithium supplementation; andmeanwhile, the metal compound layer is remained on the surface of the cathode material, so that the effect of a physical barrier layer can be achieved, the cathode material is prevented from being directly contacted with the electrolyte, the interface side reaction of the cathode material is reduced, the interface stability of the cathode material and the electrolyte is improved, and the cycle performance of the battery is improved.

An electrolyte promoting carbonate decomposition and a lithium-air battery are provided. In particular, the electrolyte promoting carbonate decomposition is disclosed and includes a lithium salt, an organic solvent and a catalyst, wherein the catalyst is a double-core or multi-core phthalocyanine transition metal coordination compound. The corresponding lithium-air battery is also disclosed. A solution-phase carbonate decomposition catalytic system is adopted by the lithium-air battery to overcome the bad electric contact between carbonates and solid electrodes, thus effectively reducing decomposition potentials of the carbonates, effectively reducing lithium carbonate accumulation in the lithium-air battery and further improving cyclic performance of the battery.

Electrode active material that is used together with an electrolyte solution having an electrolyte decomposition potential Ve is represented by the general expression LixFeMyO2 and is amorphous. In the expression, x and y are values which independently satisfy 1<x≦2.5 and O<y≦3, respectively, and z=(x+(valence of Fe)+(valence of M)×y)/2 to satisfy stoichiometry, and M represents one or two or more types of glass former element. The average electronegativity of M is less than (Ve+6.74/5.41.

The invention discloses an electrolyte for a rechargeable magnesium battery using ether as a solvent and relates to the field of rechargeable magnesium batteries. The electrolyte comprises magnesium trifluoromethanesulfonate and aluminum trichloride in a molar ratio of 1: (1 to 5). The concentration of magnesium ions in the electrolyte is 0.1 to 2.0 mol.L-1. The electrolyte has a high anodic oxidation decomposition potential, high electrical conductivity, high reversible magnesium deposition-dissolution efficiency, excellent cycle performance and low electrolyte solution cost, and the anodic oxidation decomposition potential on stainless steel can reach over 2.0V vs.Mg/Mg2+. The stable magnesium deposition-dissolution efficiency of the system is higher than 90%, which promotes the development of a low-cost and high-performance rechargeable magnesium battery.

The invention relates to the technical field of energy storage, and relates to a compound for pre-lithiation, a preparation method of the compound, a positive electrode pre-lithiation material, a preparation method of the positive electrode pre-lithiation material, and a lithium battery. The chemical formula of the compound is LixMyOz, wherein x is more than or equal to 3 and less than or equal to 12, y is more than or equal to 1 and less than or equal to 2, z is more than or equal to 4 and less than or equal to 11, and M is one or more selected from a group consisting of Nb, Ta, Zr, W, Sn, V, Ru, Ce or Bi. When the compound is used as a positive electrode pre-lithiation material, a decomposition potential is relatively low, charging specific capacity is high, a discharging process is irreversible, a relatively good lithium battery in-situ pre-lithiation effect can be realized, and the compound has good air stability, is compatible with an existing lithium battery production process and has a commercial application prospect. According to the lithium battery adopting the positive electrode pre-lithiation material, in the charging process of the battery, the compound is irreversibly decomposed to release active lithium ions, so active lithium loss caused by negative electrode SEI growth is supplemented, and the effects of improving the energy density of the lithium battery and prolonging the cycle life of the lithium battery can be achieved.

The invention discloses an anode lithium supplementing material and a preparation method and application thereof, and belongs to the field of energy storage. The positive electrode lithium supplementing material comprises a core material, the core material is at least one of a boron-doped lithium orthosilicate material and a boron-doped lithium metasilicate material, the chemical formula of the boron-doped lithium orthosilicate material is Li4Si1-xBxO4, the chemical formula of the boron-doped lithium metasilicate material is Li2Si1-yByO3, x is greater than or equal to 0.001 and less than or equal to 0.2, and y is greater than or equal to 0.001 and less than or equal to 0.2. According to the arrangement, lithium orthosilicate and/or lithium metasilicate are/is used as a main body, and the boron-doped lithium silicate material formed by non-metallic element boron doping is used as a lithium supplement agent, so that the ionic conductivity of the lithium silicate material can be improved, the decomposition potential of the lithium silicate material can be reduced, the active lithium release of the lithium silicate lithium supplement material can be promoted, and the energy density and the cycle life of the lithium ion battery can be remarkably improved.