111results about How to "Improve charge-discharge cycle performance" patented technology

The invention discloses sulfenyl anode of a lithium-sulfur rechargeable battery and a preparation method thereof. The sulfenyl anode is prepared by the steps of: equally mixing sulfenyl compound active material, cyclodextrin binder and carbon conductivity agent, coating the mixture on an aluminum foil current collector and obtaining the sulfenyl anode after drying and pressing. The coating thickness is 50 to 100 microns and the aluminum foil thickness is 20 to 30 microns; the mass ratio of the sulfenyl compound active material, the cyclodextrin binder and the carbon conductivity agent is 7 to 8:0.6 to 1:0.6 to 1.5, wherein the sulfenyl compound active material is formed by the steps of: equally mixing carbon nano tube, sulfur and polyacrylonitrile according to the mass ratio of 0.1 to 0.2:6 to 8:1 and sintering the mixture in protection of inert gas at the temperature of 300 to 320 DEG C for insulation for 6 to 8 hours. By using the lithium-sulfur rechargeable battery with the sulfenyl anode and lithium metal cathode, the reversible capacity of the sulfenyl compound active material reaches 680mAh.g under 0.1C multiplying power charge-discharge condition; and compared with the discharge capacity of second circulation, the discharge capacity after 100 times of circulation decreases less than 10 percent.

A particulate positive electrode active material for a lithium secondary cell which satisfies high charge and discharge cyclic durability, high safety, high temperature storage properties, a high discharge average voltage, large current discharge properties, a high weight capacity density, a high volume capacity density, etc. in a well-balanced manner is provided. A particulate positive electrode active material for a lithium secondary cell, which is represented by the formula Li_pCo_xM_yO_zF_a (wherein M is at least one element selected from Groups 2 to 8, 13 and 14 of the Periodic Table, 0.9≦p≦1.1, 0.980≦x≦0.9999, 0.0001≦y≦0.02, 1.9≦z≦2.1, 0.9≦x+y≦1 and 0.0001≦a≦0.02), wherein fluorine atoms and element M are unevenly distributed on the particle surface, the atomic ratio of fluorine atoms to cobalt atoms (a/x) is from 0.0001 to 0.02, and in powder X-ray diffraction using CuKα-ray, the half value width of the angle of diffraction on (110) plane is from 0.06 to 0.13°, and the half value width of the angle of diffraction on (003) plane is from 0.05 to 0.12°.

A negative electrode for lithium secondary battery includes a negative electrode collector having a proportional limit of not less than 2.0 N/mm and having a negative electrode material attached thereon, and the negative electrode material including a material to be alloyed with lithium.

The invention discloses an electrolyte for a lithium ion battery and a preparation method thereof. The electrolyte consists of a main electrolyte, an electrolyte additive, a main solvent and a solvent additive. The preparation method comprises the following steps of: A. under the condition of vacuum or inert gas protection, respectively mixing the main solvent and the solvent additive with a drying agent (lithium oxide) which is dried to be at constant weight in advance, and mixing and filtering to remove the lithium oxide and lithium hydroxide sediment; B. uniformly mixing the dried main solvent and the dried solvent additive from the step A; and C. adding a main electrolyte mixture and an electrolyte additive into the solvent mixed in the step B, and agitating and dissolving under the vacuum and inert gas protection to prepare a solution with the mass mol concentration of the main electrolyte of 0.5-1.5 M. The electrolyte has the advantages of abundant resources, low price and no toxin, effectively improves the work temperature range of the battery and effectively prolongs the circulating service life of the battery, so that various types of the lithium ion batteries are manufactured; and the electrolyte is particularly suitable for manufacturing a lithium ion power battery with high power capacity and high multiplying power charging and discharging capacity.

The invention discloses a composite cathode material for secondary aluminum batteries. The composite cathode material is formed by compounding microporous carbon spheres, sulfur and graphene, has good electric conductivity and is capable of effectively suppressing that polysulfide dissolves in electrolyte to cause the shuttle effect. The preparation method of the composite cathode material comprises the following steps: firstly compounding the microporous carbon spheres and the sulfur, and then cladding the outer layer of the composition with a graphene sheet layer. The preparation method is simple in process and low in cost, toxic raw materials are not used, environment friendliness is achieved, the energy density is high, the utilization ratio of the sulfur is high, and the rate capability and the cycle performance of the secondary aluminum batteries are improved greatly.

The invention discloses a carbon sulfur compound anode for a secondary battery. The anode is formed by compounding a carbon nanotube array, sulfur and graphene, is provided with a three-dimensional network conductive framework and is good in electrochemical performance. A preparation method of the anode comprises the following steps: compounding elemental sulfur in the carbon nanotube array at first and then wrapping an outer layer with few graphene sheet layers. The preparation method is simple in process, low in cost and environment-friendly due to nonuse of toxic raw materials; moreover, the compound anode does not need to be added with a conductive agent and a bonder, and is high in energy density and sulfur utilization rate, and the rate performance and the cycle performance of the secondary aluminum battery are greatly improved.

The present invention relates to negative pole material for lithium ion cell, and is especially one no-cyanide electroplating process for preparing Sn-Cu alloy as negative pole material for lithium ion cell. The no-cyanide electroplating process includes the following steps: dissolving potassium pyrophosphate in water, adding stannous chloride and copper sulfate to obtain mixed solution, adding epoxy chloroalkane, triethanolamine, formaldehyde and gelatin to form electroplating solution; and electroplating on copper substrate to form silvery white bright Sn-Cu alloy. The process has low cost, no environmental pollution, and the lithium ion cell with negative pole of the Sn-Cu alloy has high initial capacity, high initial charging and discharging efficiency and good charging and discharging circulating performance.

The invention discloses a high-voltage lithium battery cathode material doped with a trace amount of tungsten and a preparation method thereof. The general formula of the material is LiNi0.5Mn1.5(1-x)WxO4, wherein x is more than 0 and is less than or equal to 0.01. The material is prepared by adopting a sol-gel method, and the preparation method comprises the following steps of: dissolving a soluble lithium salt, a soluble nickel salt, a soluble manganese salt, tungsten hexachloride and ammonium oxalate in deionized water to prepare a mixed solution; heating and stirring until viscous wet gel is obtained; performing vacuum drying on the wet gel to obtain a dried gel; and finally performing pre-sintering, secondary sintering and ball milling to obtain the cathode material. The high-voltage lithium battery cathode material doped with a trace amount of tungsten has high electrochemical performance, and compared with undoped LiNi0.5Mn1.5O4, the LiNi0.5Mn1.5(1-x)WxO4 doped with a trace amount of tungsten is greatly improved in specific capacity and cycle performance.

The present invention is made to improve charge-discharge cycle performances under high temperature environment in a non-aqueous electrolyte secondary battery using a negative electrode containing a negative electrode active material of particulate silicon and/or silicon alloy and a binding agent.

A non-aqueous electrolyte secondary battery according to the present invention includes a positive electrode 11, a negative electrode 12, a separator 13, and a non-aqueous electrolyte, wherein the negative electrode includes a negative electrode active material containing particulate silicon and/or silicon alloy and a binding agent, and the non-aqueous electrolyte contains fluorinated cyclic carbonate and a prescribed diisocyanate compound, and when Li storage volume per unit area of the negative electrode of the non-aqueous electrolyte secondary battery under charging condition is determined as A and the theoretical maximum Li storage volume per unit area of the negative electrode is determined as B, a utilizing rate (%) of negative electrode which is expressed by (A/B)×100 is 45% or less.

A nonaqueous electrolyte secondary battery in which the decomposition of an electrolyte solution is reduced exhibits high coulombic efficiency and excellent charge and discharge cycle performance, and has high energy density. This nonaqueous electrolyte secondary battery includes a negative electrode that is formed by depositing a thin film of active material on a collector by a CVD method, sputtering, evaporation, thermal spraying, or plating, wherein the thin film of the active material can lithiate and delithiate and is divided into columns by cracks formed in the thickness direction, and the bottom of each column is adhered to the collector; a positive electrode that can lithiate and delithiate; and a nonaqueous electrolyte solution containing a lithium salt in a nonaqueous solvent. The electrolyte solution contains a compound expressed by a general formula (I).

(wherein, R¹, and R², R³ are hydrogen atoms or alkyl groups each optionally having a substituent, may be identical or different from one another, may be independent substituents, or may be bound together to form a ring)

Charge-discharge cycle performance is improved in a lithium secondary battery that adopts a thin film made of silicon or a silicon alloy as its negative electrode active material and has a wound electrode structure. The lithium secondary battery includes: a negative electrode having a current collector and a thin film made of silicon or a silicon alloy as a negative electrode active material, the thin film provided on the current collector; a positive electrode; a separator; the positive and negative electrodes being overlapped with the separator interposed therebetween, and the positive and negative electrodes and the separator being wound around to form an electrode assembly; a non-aqueous electrolyte; and a battery case accommodating the electrode assembly. The ratio of charge capacity per unit area of the negative electrode to theoretical capacity per unit area of the positive electrode is within the range of from 1.9 to 4.4.

A lithium battery comprising a positive electrode comprising a positive-electrode active material of boron-containing lithium-manganese complex oxide, a negative electrode and a nonaqueous electrolyte containing a solute and a solvent, the positive-electrode active material is the boron-containing lithium-manganese complex oxide having a boron-to-manganese atomic ratio (B/Mn) in the range of 0.01 to 0.20 and a predischarge mean manganese valence of not less than 3.80

Charge-discharge cycle performance is improved in a lithium secondary battery that uses a material that occludes lithium by alloying with lithium as its negative electrode active material. A lithium secondary battery comprises a negative electrode having a negative electrode active material thin film provided on a negative electrode current collector, a positive electrode including a positive electrode active material, and a non-aqueous electrolyte, in which the negative electrode active material is a material that occludes lithium by alloying with lithium, the ratio of the discharge capacity per unit area of the negative electrode to the discharge capacity per unit area of the positive electrode is from 1.5 to 3, and the ratio of the thickness (μm) of the negative electrode active material to the arithmetical mean roughness Ra (μm) of the surface of the negative electrode current collector is 50 or less.

The invention provides a method for preparing a nanometer ceramic particle doped PE diaphragm, belonging to the technical field of high-property membrane materials. The method for preparing the nanometer ceramic particle doped PE diaphragm comprises the steps of proportioning materials, extruding cast strips, synchronously drawing towards two directions, extracting, transversely stretching for enlarging and the like; as electrochemical inactive inorganic ceramic particles are added in a skeleton material of the PE diaphragm, the PE diaphragm has better compatibility with the electrodes of a lithium ion battery than the common battery diaphragm, the high-temperature resistance and the safety of the battery can be greatly improved, the absorbability of liquid electrolytes is good, the electrolyte filling time of the battery can be shortened,the internal resistance of the battery can be reduced, and the high-rate charging-discharging properties of the batteries can be improved, so that the charging-discharging cycle properties of the battery can be greatly improved.

The present invention provides a positive electrode material LiNi1-xCoxO2 (x is greater than or equal to 0.15 or less than or equal to 0.30) covered by using LiCoO2 and its preparation method. Said material has good electric discharge multiplying factor specific property, charging and discharging circulating performance, safety and storage property.

A polymer secondary battery uses, for at least one of the active material of positive electrode and the active material of negative electrode, a polymer-carbon composite material including powdered carbon having its surfaces coated with an organic compound polymer capable of adsorbing and desorbing protons electrochemically. The polymer secondary battery has a high rate of appearance of capacity and excellent cycle characteristics.

The invention discloses lithium cobaltate for a positive electrode of a lithium ion battery and a preparation method of the lithium cobaltate for the positive electrode of the lithium ion battery. The proportional formula of the lithium cobaltate prepared by adopting the method is shown as LixCoyMzO2, wherein M represents for one or two of transition metal elements except Co or alkaline earth metals elements; S represents for an average valence of all metal elements of the lithium cobaltate except lithium and cobalt; a mole ratio of four elements in the positive material-lithium cobaltate is x to y to 2 to 2; S is greater than or equal to +2 and less than +2.5; x is greater than or equal to 0.9 and less than or equal to 1.1; y is greater than or equal to 0.8 and less than or equal to 1.1; x plus 3y plus S*z is equal to 4. The lithium cobaltate prepared by adopting the method has the high volume capacity density, the high safety, the stable charge-discharge cycle performances and the high compaction density.

The invention discloses an ion-doped spherical Li4Ti5O12/C lithium ion battery anode material and a preparation method thereof. The method comprises the following steps of: 1) uniformly dispersing a lithium source compound and a carbon source compound into ion-doped titanium oxide sol and spray-drying to obtain spherical powder; and 2) under the protection of an inert gas, performing heat treatment on the spherical powder to obtain the ion-doped spherical Li4Ti5O12/C lithium ion battery anode material. The method for preparing the ion-doped spherical Li4Ti5O12/C lithium ion battery anode material provided by the invention improves the electric conductivity of the material by compounding Li4Ti5O12 with carbon and stabilizes the crystal structure of the material by doping ions so as to further improve the charge-discharging cycle performance of the material. The method has a simple process flow; and the obtained lithium ion battery anode material is spherical, and has suitable particle sizes and reasonable particle diameter distribution, high stacking density and a very good application prospect in the field of lithium ion batteries.