CN103746140A

CN103746140A - Lithium secondary battery

Info

Publication number: CN103746140A
Application number: CN201410038377.6A
Authority: CN
Inventors: 胡玉华
Original assignee: JIANGSU PINDE ENVIRONMENTAL SCIENCE AND TECHNOLOGY Co Ltd
Current assignee: JIANGSU PINDE ENVIRONMENTAL SCIENCE AND TECHNOLOGY Co Ltd
Priority date: 2014-01-26
Filing date: 2014-01-26
Publication date: 2014-04-23
Anticipated expiration: 2034-01-26
Also published as: CN103746140B

Abstract

The invention discloses a lithium secondary battery. The lithium secondary battery comprises an anode, a cathode, an electrolyte and a 200-nanometer separator which is formed by a porous membrane of polypropylene between the anode and cathode, wherein the manufacturing method of the anode comprises the following steps of: mixing lithium cobalt oxide and Ketjen Black with polypropylene, fluorine resin and an iron fiber, and dissolving a mixture in NMP (Nuclear Matrix Protein), wherein lithium cobalt oxide of positive active materials is added with phthalic anhydride which is 2.5% relative to the weight of lithium cobalt oxide, the iron fiber has a rough surface, and is a ferroferric oxide fiber which has a porous surface and diameter of 100 to 150 nanometers, with the surface porous diameter of 20 to 30 nanometers.

Description

A kind of lithium secondary battery

Technical field

The present invention relates to a kind of lithium rechargeable battery, comprise positive pole, negative pole and electrolyte.

Background technology

In recent years, occurred that a large amount of portable electric appts are as video camera (camcorder), cell phone and kneetop computer, and attempted to reduce their size and alleviate their weight.So, actively promoted the development of battery, particularly as the development of the secondary cell of the portable power supplies of electronic equipment.Wherein, lithium rechargeable battery receives publicity owing to can obtaining high-energy-density.

Summary of the invention

A kind of secondary cell, comprise the dividing plate of the 220nm of the polyacrylic perforated membrane formation between positive pole, negative pole and electrolyte and positive pole and negative pole, wherein, anodal manufacture method comprises, mix cobalt acid lithium, Ketjen black and polypropylene, fluororesin, titanium fiber, is dissolved in mixture in NMP, wherein in positive active material cobalt acid lithium, adds 2.5 phthalic anhydride acid anhydrides of relative cobalt acid lithium weight percent; The manufacture method of negative pole comprises, collector body adopts thickness 180nm, surface roughness is the Copper Foil of 1.5nm, on it, adopt rf sputtering method, adopt at ambient temperature direct current that the reaction pressure of 0.1Pa utilizes 180W and exchange coefficient source and target is carried out to sputter obtain, before sputter, target is formed to the insulation film of 150nm thickness, finally obtain the amorphous silicon membrane of thickness 60nm.Wherein negative pole can also adopt that evaporation is sent out, metallikon and CVD method manufacture.It can also be nonaqueous electrolyte battery.

Wherein, polyethylene polypropylene etc., owing to having good reproducibility and nontoxic property, are that generally acknowledged environmental protective polymer is more and more widely used at present.Meanwhile, its caking property is strong, expansion/contraction stable performance own.Meanwhile, adopt iron fiber doping.Further evenly binding agent distributes, and prevents that adhesive particle shape is entangled with agglomerating.Reduced the fissility of binding agent, the cycle efficieny of the battery of raising.

The preparation of iron fiber material:

Adopt hydro thermal method.After ferrous nitrate, natrium citricum and distilled water are mixed according to the ratio of 1.5: 3: 50, to mixture, add gelatin, obtain the hydrosol.Utilize strong base-weak acid salt by the ph value to 8.5 of the hydrosol, under 240-300 degree Celsius, react and make for 3 hours.

Wherein, tri-iron tetroxide fiber material has rough surface, is the tri-iron tetroxide fiber of porous surface.This fibre structure has increased its specific area greatly, is conducive to absorption or is dispersed among binding agent, and its length is 4-6 with the ratio of diameter.The diameter in its surperficial hole is 20-30nm.

Diameter is 100-150nm.To obtain applicable aperture and the ratio of diameter, thereby effectively improve the dispersiveness of fiber and there is appropriate adsorptivity.Tri-iron tetroxide fiber material accounts for binder material total weight than being 0.3-4.6%.

In addition, anticathode collector body adopts sputtering method manufacture, wherein, comprise and adopt the mode of DC source, alternating current source parallel connection to carry out sputter to target, and owing to forming the insulation film of 150nm thickness on target, cause its sputter procedure more stable, prevent that irregular target is poisoning and at accumulative total mound, target surface shape insulating barrier, cause the unstable and flame-out of sputter procedure now, and can improve sputtering yield by improving source voltage.

Accompanying drawing explanation

Fig. 1 is the exploded perspective illustration of secondary cell according to an embodiment of the invention.

Fig. 2 is the sectional view along the spiral winding electrode of the II-II line of Fig. 1.

Embodiment

According to one embodiment of the invention, this secondary cell uses lithium as electrode activity thing (reactant), and comprise the electrode body 20 of screw winding, in membranaceous enclose components 30, cathode terminal 11 and anode terminal 12 are connected in this electrode body 20, from the inside of enclose components 30, to outside, draw cathode terminal 11 and anode terminal 12, for example, with identical direction.Cathode terminal 11 and anode terminal 12 are to be made as aluminium (Al), copper (Cu), nickel or stainless steel by for example sheet or net metal material.

Enclose components 30 be by for example comprise nylon membrane, aluminium foil and polyethylene film and with this order combination rectangular aluminum stack membrane make.Enclose components 30 is set and makes the polyethylene film of each enclose components 30 towards the electrode body 20 of screw winding, and the marginal portion of enclose components 30 is mutually bonding by melted join or binding agent.Adhensive membrane 31 is embedded between enclose components 30 and cathode terminal 11 and anode terminal 12 for stoping entering of extraneous air.Adhensive membrane 31 is that the material that has an adhesion by for example target terminal 11 and anode terminal 12 is made, and for example vistanex is as polyethylene, polypropylene, modified poly ethylene or modified polypropene.

Fig. 2 has shown along the sectional view of the electrode body 20 of the screw winding of the II-II line of Fig. 1.The electrode body 20 of screw winding is the laminated body that comprises the screw winding of a target 21 and anode 22, and has barrier film 23 and electrolyte 24 therebetween, and the outermost portion of the electrode body 20 of this screw winding is subject to the protection of buffer zone 25.

Negative electrode 21 comprises the cathode current collector 21A for example with a pair of outer surface and the cathode active material bed of material 21B that is arranged on this cathode current collector 21A both sides.Cathode current collector 21A has expose portion in longitudinal one end, at this expose portion, cathode active material bed of material 21B is not set, and cathode terminal 11 is connected with this expose portion.Cathode current collector 21A is made as aluminium foil, nickel foil or stainless steel foil by metal forming for example.This cathode active material bed of material 21B comprises that one or both or the more kinds of cathode material that can embed and deviate from lithium are as active material of cathode, and if need, cathode active material bed of material 21B can comprise conductive agent and binding agent.

Claims

1. a lithium secondary battery, comprise the dividing plate of the 220nm of the polyacrylic perforated membrane formation between positive pole, negative pole and electrolyte and positive pole and negative pole, wherein, anodal manufacture method comprises, mixes cobalt acid lithium, Ketjen black and polypropylene, fluororesin, iron fiber, diameter is 100-150nm, fiber, is dissolved in mixture in NMP, wherein in positive active material cobalt acid lithium, adds 2.5 phthalic anhydride acid anhydrides of relative cobalt acid lithium weight percent; The manufacture method of negative pole comprises, collector body adopts thickness 180nm, surface roughness is the Copper Foil of 1.5nm, adopts rf sputtering method on it, adopts at ambient temperature direct current that the reaction pressure of 0.1Pa utilizes 180W and exchanges coefficient source and target is carried out to sputter obtain, before sputter, target is formed to the insulation film of 150nm thickness, finally obtain the amorphous silicon membrane of thickness 60nm, wherein, iron fiber has coarse surface, is the tri-iron tetroxide fiber of porous surface.

2. battery according to claim 1, wherein negative pole can also adopt that evaporation is sent out, metallikon and CVD method manufacture.

3. secondary cell according to claim 1 can also be nonaqueous electrolyte battery.