CN102916166B

CN102916166B - Lithium ion battery paste preparation method

Info

Publication number: CN102916166B
Application number: CN201210393094.4A
Authority: CN
Inventors: 宗磊
Original assignee: Irico Group Corp
Current assignee: Irico Group Corp
Priority date: 2012-10-16
Filing date: 2012-10-16
Publication date: 2015-03-11
Anticipated expiration: 2032-10-16
Also published as: CN102916166A

Abstract

The invention relates to a lithium ion battery paste preparation method. The preparation method is characterized by comprising the following steps: (1) glue preparation: adding deionized water and CMC (Carboxy Methylated Cellulose) into an agitation tank at the proportion of (120:1)-(120:4), starting up revolution for low-speed agitation, and taking out glue after exhaustion for later use; (2) paste preparation: adding graphite and a conductive agent into a paste tank at the proportion of (100:2)-(100:8) for low-speed revolution and agitation, starting up autorotation for agitation after dry powder is completely moistened, and adding an SBR (Styrene Butadiene Rubber) binder in the same quantity as the CMC if the viscosity is qualified; and (3) discharge: vacuumizing the obtained paste before discharge while low-speed revolution and agitation is performed, and filtering the paste through a sand screen less than 150 meshes during discharge. The preparation method is implemented by controlling parameters in the battery paste preparation process, and test proves that the obtained paste has more stable ingredients and is higher in quality.

Description

A kind of preparation method of pulp of lithium ion battery

Technical field

The present invention relates to a kind of preparation method of pulp of lithium ion battery.

Background technology

Along with the development of lithium ion battery industry, the use of water-soluble binder is more and more extensive, and especially in the preparation of cathode size, the use of water-soluble binder is more.It is not only in use low to the requirement of environment, and in performance, does not have obvious difference according to the battery that some reports use water-soluble paste to make.Simultaneously water-soluble binder and PVDF positive pole binder phase ratio are less likely to occur to react and discharge HF and cause battery capacity to lose or safety problem occurs, and its fail safe is higher.

The many employings of water-soluble binder CMC and SBR conventional is at present used in combination.CMC is macromolecular compound, soluble in water and polar solvent, can keep the uniformity of slurry, avoid sedimentation; SBR is the linear chain emulsion of Small molecular, and soluble in water and polar solvent, can ensure that slurry is firmly bonded on carrying object.In actual use, the addition of the two is all less, is generally first make CMC glue, adds SBR after slurry agitation is even with CMC glue.The in use control of some parameters needs to be paid close attention to, and some parameter can accelerate the effect of homogenate, and some parameter is the ingredient stability of the slurry of relation and the success or failure of slurrying then.Such as, but because amount is larger in the use procedure of reality, some tiny problems may be covered, but these problems may have influence on the quality of slurry really, the parameter that different times vacuumizes, the mixing speed etc. of slurry.

Summary of the invention

The invention provides a kind of preparation method of pulp of lithium ion battery, the paste composition that obtains can be made more stable, and quality is higher.

A preparation method for pulp of lithium ion battery, its special feature is, comprises the steps:

Homogenate equipment cleaning is clean, in slurry tank, add the deionized water of 1.5Kg, and add 20gCMC dry powder, use the revolution of 15r/min to carry out stirring at low speed, after 15 minutes, carry out scraper, then use revolution 30r/min, rotation 500r/min to continue to stir; After 1 hour, rotating speed is risen to revolution 50r/min, rotation 1000r/min, in glue without caking, complete transparent time carry out vacuumizing and exhausting and make vacuum degree be greater than-0.095MPa all the time, after exhaust, glue is poured in container and deposits;

Cleaned out by slurry tank, add graphite 1Kg in slurry tank, conductive agent 32g carries out low speed and be dry mixed, the rotating speed that namely revolves round the sun is 10r/min, and the time is 20 minutes, and the glue then adding 900g in tank stirs, and the rotating speed 15r/min that namely revolves round the sun, certainly transfers 0 to; Stir and carry out scraper after 20 minutes, in slurry tank, add the remaining glue of 390g continue to stir, namely revolve round the sun 50r/min, rotation 500r/min, after half an hour, rotation is risen to 1500r/min until slurry agitation is even, the viscosity of testing size, viscosity is adjusted to 1500 ~ 2000cps, adds 16g SBR, adopt revolution 15r/min stirring at low speed 30 minutes;

Rear preparation discharging prepared by slurry, carry out before discharging vacuumizing process, mode is one side stirring at low speed, namely revolve round the sun 15r/min, while vacuumize, stop when vacuum degree reaches-0.08MPa vacuumizing and keep vacuum state to stir always, until the air in slurry is by discharging after abundant discharge, by slurry 100 object sand net filtrations during discharging.

The inventive method is by controlling to realize to the parameter in cell size preparation process, and through probationary certificate, the paste composition obtained is more stable, and quality is also higher.

Embodiment

Embodiment 1:

Homogenate equipment cleaning is clean, in slurry tank, add the deionized water of 1.5Kg, and add 20gCMC dry powder, use the revolution of 15r/min to carry out stirring at low speed, after 15 minutes, carry out scraper, then use revolution 30r/min, rotation 500r/min to continue to stir.After 1 hour, rotating speed is risen to revolution 50r/min, rotation 1000r/min, in glue without caking, complete transparent time carry out vacuumizing and exhausting (vacuumize, vacuum degree is greater than-0.095MPa all the time always), after exhaust, glue is poured in container and deposits.

Cleaned out by slurry tank, add graphite 1Kg in slurry tank, conductive agent 32g carries out low speed and be dry mixed, revolution rotating speed is 10r/min, and the time is 20 minutes, and the glue then adding 900g in tank stirs, and revolution rotating speed 15r/min, certainly transfers 0 to.Stir and carry out scraper after 20 minutes, in slurry tank, add the remaining glue of 390g continue to stir (revolution 50r/min, rotation 500r/min), after half an hour, rotation is risen to 1500r/min until slurry agitation is even, the viscosity of testing size, viscosity is adjusted to 1500 ~ 2000cps, add 16g SBR, adopt stirring at low speed (revolution 15r/min) 30 minutes.

Rear preparation discharging prepared by slurry, carry out before discharging vacuumizing process, mode is for one side stirring at low speed (revolution 15r/min) is while vacuumize, stop when vacuum degree reaches-0.08MPa vacuumizing and keep vacuum state to stir always, observe slurry form after half an hour, surperficial bubble-free, viscosity are good.Start discharging, discharging is by slurry 100 object sand net filtrations, and gained slurry form is good, is applicable to coating.

Embodiment 2:

Equipment of resin making is cleaned up before glue and dries up with compressed air, slurry tank washed with de-ionized water is clean and dry up with compressed air.Proportioning as described in Example 1 and process carry out glue preparation and slurry preparation.Rear preparation discharging prepared by slurry, carry out before discharging vacuumizing process, mode is for one side stirring at low speed is while vacuumize, vacuum degree remains at higher state (≤-0.095MPa), observe slurry form after half an hour, but the viscosity of surperficial bubble-free slurry increases, temperature declines to some extent, the state of slurry there occurs some changes, may affect coating.

Comparative example 1:

Getting small beaker one to carry out checking, taking graphite 94g, conductive agent 3g, carrying out hand mix, then adding the CMC glue that 120g prepares, proceed hand operated mixing, add 1.5g SBR binding agent when slurry form stirs by the time, stir.The slurry be stirred is put into vaccum-pumping equipment and carries out vacuumizing and exhausting, mode adopts equally to vacuumize always and makes vacuum degree remain on higher horizontal (≤-0.096MPa), find that slurry solidifies substantially when taking out sample after 5 minutes, temperature is very low, frost has even appearred in the wall of beaker, and the slurry of this state can not use substantially.

Comparative example 2:

Get two small beakers, a loading 120g CMC glue and 1.5g SBR binding agent are mixed, another only loads 120g CMC glue and carries out vacuumizing process, mode is still vacuumize to make vacuum state remain on higher horizontal (≤-0.095MPa always), take out beaker after 5 minutes and find that CMC glue is except minute bubbles wherein reduce, state own there is no and changes, and the liquid adding SBR binding agent there occurs solidification, be essentially the solid state in white, temperature is lower, and the wall of beaker has frost to occur.

Comparative example 3:

Get small beaker one, add 120g CMC glue wherein and 1.5g SBR binding agent is mixed, carry out vacuumizing process, stop after vacuum being evacuated to-0.085MPa vacuumizing and keeping this state always, by the time after 5 minutes, beaker is taken out, find that there is the surface of a small amount of distribution of gas at mixed glue solution, owing to not stirring, the gas on surface is adsorbed, but the gas of glue inside is discharged substantially, and what change does not occur state yet.Hybrid adhesive now keeps good, is applicable to continuing to use.

From above comparing result, in order to accelerate vacuumizing and exhausting process in the process of glue, vacuum degree can be kept higher or vacuumizes always stir; In homogenization process, after adding SBR binding agent, its mixing speed strictly controls with the parameter needs vacuumized, General Proper reciprocal of duty cycle is not more than-0.085MPa and is advisable, mixing speed is less than 50 revs/min and is advisable, otherwise the quality of slurry may be affected or cause slurrying failure, and above-described embodiment 1 is owing to have employed suitable parameter, the slurry therefore obtained is best.

Claims

1. a preparation method for pulp of lithium ion battery, is characterized in that, comprises the steps:

Cleaned out by slurry tank, add graphite 1Kg in slurry tank, conductive agent 32g carries out low speed and be dry mixed, the rotating speed that namely revolves round the sun is 10r/min, and the time is 20 minutes, and the glue then adding 900g in tank stirs, and the rotating speed 15r/min that namely revolves round the sun, certainly transfers 0 to; Stir and carry out scraper after 20 minutes, in slurry tank, add the remaining glue of 390g continue to stir, namely revolve round the sun 50r/min, rotation 500r/min, after half an hour, rotation is risen to 1500r/min until slurry agitation is even, the viscosity of testing size, viscosity is adjusted to 1500 ~ 2000cps, adds 16gSBR, adopt revolution 15r/min stirring at low speed 30 minutes;