CN103746140B

CN103746140B - A kind of lithium secondary battery

Info

Publication number: CN103746140B
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: 2015-08-19
Anticipated expiration: 2034-01-26
Also published as: CN103746140A

Abstract

A kind of lithium secondary battery, comprise the dividing plate of the 220nm of positive pole, negative pole and electrolyte and the polyacrylic perforated membrane formation between positive pole and negative pole, wherein, the manufacture method of positive pole comprises, the acid of mixing cobalt lithium, Ketjen black and polypropylene, fluororesin, iron fiber, is dissolved in mixture in NMP, wherein adds the phthalic anhydride acid anhydrides of relative cobalt acid lithium weight percent 2.5 in positive active material cobalt acid lithium; Wherein, iron fiber has coarse surface, and be the tri-iron tetroxide fiber of porous surface, diameter is about 100-150nm, and the diameter in the hole on surface is about 20-30nm.

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, occur that a large amount of portable electric appts is as video camera (camcorder), cell phone and kneetop computer, and attempted to reduce their size and alleviate their weight.So, actively facilitate 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 obtaining high-energy-density.

Summary of the invention

A kind of lithium secondary battery, comprise the dividing plate of positive pole, negative pole and electrolyte and the 220nm be made up of polypropylene porous film between positive pole and negative pole, it is characterized in that, wherein the manufacture method of positive pole comprises, the acid of mixing cobalt lithium, Ketjen black, polypropylene, fluororesin and iron fiber, mixture is dissolved in NMP, wherein in positive active material cobalt acid lithium, adds the phthalic anhydride of relative cobalt acid lithium weight percent 2.5; The manufacture method of negative pole comprises, collector body adopts thickness 180nm, surface roughness is the Copper Foil of 1.5nm, it adopts rf sputtering method, the reaction pressure of 0.1Pa is adopted to utilize the direct current of 180W and exchange coefficient source and sputter target at ambient temperature, finally obtain the amorphous silicon membrane of thickness 60nm, wherein before sputtering, on target, first form the insulation film of 150nm thickness; Wherein, iron fiber diameter is 100-150nm and has coarse surface, is the tri-iron tetroxide fiber of porous surface.Wherein negative pole can also adopt vapour deposition method, metallikon and CVD method to manufacture.It can also be nonaqueous electrolyte battery.

Wherein, polyethylene polypropylene etc., owing to having good reproducibility and nontoxic property, are that the environmental protective polymer of generally acknowledging at present is more and more widely used.Meanwhile, its caking property is strong, expansion/contraction stable performance own.Meanwhile, iron fiber doping is adopted.Further even adhesion agent distribution, prevents adhesive particle shape to be entangled with agglomerating.Reduce the fissility of binding agent, improve the cycle efficieny of battery.

The preparation of iron fiber material:

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

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

Diameter is 100-150nm.To obtain the ratio of aperture and the diameter be applicable to, thus 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 adopt DC source, alternating current source parallel connection mode target is sputtered, and owing to forming the insulation film of 150nm thickness on target, cause its sputter procedure more stable, prevent irregular target poison ing from causing the instability of sputter procedure at accumulative mound, target surface shape insulating barrier and stopping working now, and sputtering yield can be improved 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 of the spiral winding electrode of II-II line along 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, cathode terminal 11 and anode terminal 12 is drawn, such as, with identical direction from the interior of enclose components 30.Cathode terminal 11 and anode terminal 12 are as aluminium (A1), copper (Cu), nickel or stainless steel are made by such as sheet or reticulated metallic material.

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

Fig. 2 shows the sectional view of the electrode body 20 of the screw winding of the II-II line along Fig. 1.The electrode body 20 of screw winding is the laminated body of the screw winding comprising 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 such as with a pair outer surface and the cathode active material 21B being arranged on this cathode current collector 21A both sides.Cathode current collector 21A has expose portion in one end of longitudinal direction, does not arrange cathode active material 21B at this expose portion, and cathode terminal 11 is connected with this expose portion.Cathode current collector 21A is as aluminium foil, nickel foil or stainless steel foil are made by such as metal forming.This cathode active material 21B comprise one or both or more plant can embed and deviate from the cathode material of lithium as active material of cathode, and if need, cathode active material 21B can comprise conductive agent and binding agent.

Claims

1. a lithium secondary battery, comprise the dividing plate of positive pole, negative pole and electrolyte and the 220nm be made up of polypropylene porous film between positive pole and negative pole, it is characterized in that, wherein the manufacture method of positive pole comprises, the acid of mixing cobalt lithium, Ketjen black, polypropylene, fluororesin and iron fiber, mixture is dissolved in NMP, wherein in positive active material cobalt acid lithium, adds the phthalic anhydride of relative cobalt acid lithium weight percent 2.5; The manufacture method of negative pole comprises, collector body adopts thickness 180nm, surface roughness is the Copper Foil of 1.5nm, it adopts rf sputtering method, the reaction pressure of 0.1Pa is adopted to utilize the direct current of 180W and exchange coefficient source and sputter target at ambient temperature, finally obtain the amorphous silicon membrane of thickness 60nm, wherein before sputtering, on target, first form the insulation film of 150nm thickness; Wherein, iron fiber diameter is 100-150nm and has coarse surface, and be the tri-iron tetroxide fiber of porous surface, the ratio of its length and diameter is 4-6, and the diameter in the hole on its surface is 20-30nm, adopts hydro thermal method to obtain.

2. a lithium secondary battery, comprise the dividing plate of positive pole, negative pole and electrolyte and the 220nm be made up of polypropylene porous film between positive pole and negative pole, it is characterized in that, wherein the manufacture method of positive pole comprises, the acid of mixing cobalt lithium, Ketjen black, polypropylene, fluororesin and iron fiber, mixture is dissolved in NMP, wherein in positive active material cobalt acid lithium, adds the phthalic anhydride of relative cobalt acid lithium weight percent 2.5; The manufacture method of negative pole comprises, and collector body adopts thickness 180nm, and surface roughness is the Copper Foil of 1.5nm, it adopts vapour deposition method, metallikon or CVD method manufacture, finally obtains the amorphous silicon membrane of thickness 60nm; Wherein, iron fiber diameter is 100-150nm and has coarse surface, and be the tri-iron tetroxide fiber of porous surface, the ratio of its length and diameter is 4-6, and the diameter in the hole on its surface is 20-30nm, adopts hydro thermal method to obtain.