No matter be the mobile phone that we cannot leave daily and computer, current still even more popular camera and camera, lithium battery depends on bulk small, weight characteristic of generous of light, look, make the crucial presence in these digital facilities. In recent years, as lithium ion batteries is in car (the =xEV) such as EV, HEV, PHEV, electric power stores, the utility of the respect such as industrial machinery, plane, train expands ceaselessly, the dimension of batteries also came true large change.
Regard a product as throw on the market first from 1991, apply extensively at social construction and the people's livelihood of science and technology to nowadays numerous domain, development of these 30 years can say lithium battery main around face of the following tripartite: &Ensp;1. Raise capacity and power density;2. Reduce cost;3. Maintain and enhance security. Be worth what carry is, in integrated above character demand is entered rank on the road of development, ” of batteries of “ high capacity became the character that first consideration realizes in development of category of lithium ion batteries especially, just had through old dedicated research and development today the superior performance of high capacity batteries.
Photograph of ” of photograph “ fluorine is become, does industry appeal more does actor solve: ? Does Guang embrace herd of Р of of of Mu of red Piao instrument?
Fluorine compound and fluorine colophony normally with chemical stability tall and famed, also used data of a lot of fluorine in the production of lithium ion batteries, especially electrolyte binder. Material of lithium ion batteries can make a high-powered battery, fluorine data can say is result cannot do not have.
The voltage of lithium ion batteries can be as high as 4.6V. Want to manage the property of material steadily, can accomplish besides fluorine compound beyond, other data is little little. More what is more,the rather that, use the electrolyte within positive electrode electrode or binder, can expose in strong oxidisability environment, because this is right the demand of material stability is extremely high.
As the advanced company that has fluorine chemistry of 90 years to study experience, chemical industry of big gold fluorine faced lithium ion batteries to develop binder, electrolyte to use compound binder of additive and dissolvent, CNT the product such as material of dispersive fluid, sealing ring, made contribution to raise the function of lithium ion batteries and security safeguard.
” of the working procedure before the workmanship of general lithium ion batteries divides the “ before be the electrode that make and ” of the working procedure after assemble battery unit and forming the “ of batteries appearance. The electrode in working procedure is made before use besmear cloth method, and it is —— of double-faced Tu Bu will active material and electric agent arrive dispersedly deliquescent printing ink is made in the dissolvent that has adhesive (serous) , get on printing ink besmear in tinsel collect fluid again, suppress of roller of dry and junior travel becomes electrode.
Among them, the binder of positive electrode uses PVdF data commonly, NMP(N- of solvent use organic compound is methylic - ) of ketone of 2- pyrrole alkyl. Because be organic dissolvent, deal with undeserved meeting causes pollution to the environment. And this organic dissolvent is flammability dissolvent, the building of the factory needs to use explosion proof to design norms, demand of safe to the factory construction is extremely high, and the safe hidden trouble with constant presence.
Additional, the boiling point of NMP is 204 ℃ left and right sides, dry temperature is 120-130 ℃ , temperature is higher. Accordingly, in dry technology need wastes a large number of energy, the question with existence CO2 bigger discharge capacity.
Bring safe hidden trouble besides combustible, big specific power consumption produces negative environment beyond the influence, the cost question of NMP itself is very big also. Accordingly, NMP cannot wait for means to use up through burning or discard, must undertake “ reclaims ” . Of NMP reclaim equipment and reclaim charge also becomes the burden that goes up to make.
And to negative pole, use water to serve as solvent normally, but the vaporization latent heat of water is bigger, the generation in bringing about dry process exceeds big specific power consumption. Considering the discharge capacity of CO2 and cost issue, industry also appeared to convert the cry of his law.
Lithium ion batteries does law craft, innovation of chemical industry of big gold fluorine is offerred program of product of negative pole binder
How should that solve afore-mentioned problems that producing in negative pole production process?
One of methods use dry method technology namely. This kind of method need not besmear cloth legal system makes electrode, also do not use the liquid such as water and organic dissolvent. Accordingly, do not need to undertake to solvent dry and reclaim. Use active material, electric agent and binder only body of this kind of pink mixes the mixed powder end that makes an electrode, some kind of method forms recycle chip will make electrode.
The advantage of dry method craft is not to need dry reach a knock off order, but on the other hand, traditional and wet of the thin electrode layer with relatively easy craft shape become difficult. Should make electrode material even and make for paper-thin electrode, need very high technology demand.
At present the dry method craft of industry discussion is divided roughly it is two kinds. A kind of method is will thermoplastic photograph of small pink and active material, electric agent mixes colophony binder, heat make binder colophony melt, the binder that uses melt makes between active material, between electric agent agglutinate. Another kind of method is to use PTFE(to get together 4 fluorine change Xi) as binder colophony, bring to bear on proper shearing force undertakes mixing refine, make PTFE fine is refined (fiber is changed) as adhesive, make through the method such as roller pressing extremely piece ply attenuates.
To doing two kinds of methods of law craft, have the binder that agrees with to machine a method severally:
Thermoplastic colophony binder
Batteries of active ion of liquid state lithium, its anode binder is PVdF almost kind material. Because PVdF has electrochemistry stability,this is, although be in,very tall oxidation also won't be decomposed below potential, actual level is used as in lithium ion batteries. Accordingly, use thermoplastic the dry method craft that colophony regards binder as also basically is pair of PVdF kind the small pink of material undertakes developing using.
PTFE binder
Craft of another kind of dry method is make below the action of shearing force PTFE fiber is changed, these fine fibre and active material, electric agent is intricate form lump to, undertake through the means such as roller pressing piece come preparation electrode. Of course, to this binder, expect to be able to realize fiber to change through shearing force not only, still ask binder is had on the foundation here necessary fight oxidation function.
And PTFE can issue fiber to change in shearing force action not only, still have very tall fight oxidation function. Accordingly, below this kind of method, PTFE is extremely possible use as the material of the binder of electrode of dry method craft of positive electrode.
But the question with the biggest PTFE is, below the reductive potential of negative pole, PTFE is met by reductive, the likelihood cannot develop the function of binder for a long time. Accordingly, do not recommend use in negative pole. Come so, positive electrode and negative pole use different binder with respect to need.
Company of chemical industry of big gold fluorine uses the fluorine colophony technology that accumulates for years, especially the design of PTFE and synthetic technology, devote oneself to to advance the development that measures the PTFE that implementation diaphragm shapes with fewer accretion. Because chemical industry of big gold fluorine has latex group technique and PVdF kind material, have development to use the fundamental condition of binder of Yu Zheng negative pole at the same time, can offer more advanced product proposal thereby.
Be based on the professional technology that in fluorine chemistry domain deep ploughing accumulates for years and market experience, chemical industry of big gold fluorine from beginning to end trend of forward position of industry of with a view to and demand, the performance that improving batteries of advanced lithium ion and environmental protection respect produce main effect, the development that also will continue to pass fluorine data henceforth is social progress to make larger contribution.