Cathode conducive to lithium ion battery quick charge and the lithium ion battery based on thisTechnical field
The present invention relates to field of lithium ion battery, and in particular to a kind of cathode and base conducive to lithium ion battery quick chargeIn this lithium ion battery.
Background technology
Lithium ion battery has the characteristics that energy density is high in itself, but charging rate is slow, low power density is lithium ionThe main shortcoming of battery.For pure lithium ion battery due to factors such as anode and electrolyte, the conduction of velocity of electric current and electric energy is slow.At presentPrior art is that super capacitance cell and lithium ion battery are combined, it is therefore an objective to put charging rate spy using super capacitance cellThe characteristics of not fast, cathode is shared using lithium ion battery and super capacitor, charge/discharge rates can be improved in this way and promote energyMetric density, increase power density.In fact, lithium ion battery and super capacitor share cathode just in the conceptual phase, without realExisting commercialization, it is often more important that, charging rate is still slow in lithium ion battery part, the more single lithium of total energy density fromSub- battery is low.
At present, the Mechanism of electrochemical behaviors of anhydrous of lithium ion battery is based on a kind of theory, during charging, Li+From positive electrode " abjection ", soAfterwards by electrolyte membrance " insertion " negative material atom gap, discharge process is then opposite.It is a kind of energy based on electric current, energyIt is stored in the atom outermost electron level of lithium ion battery negative material, when current energy enters negative material, lithium ionEmbedded cathode atom gap, current energy are stored under electromagnetic action.Existing lithium ion battery charging rate is slow, usually formerBecause of the problems such as being anode, cathode, electrolyte.
Invention content
In order to solve the problems, such as that lithium ion battery charging rate is slow, the present invention discloses one kind and is quickly filled conducive to lithium ion batteryThe cathode of electricity, which can bear the impact and destruction that lithium ion battery quick charge is brought, and then promote lithium ion batteryCharging rate, invention additionally discloses a kind of lithium ion batteries of quick charge based on the cathode.
The present invention is achieved through the following technical solutions：
Conducive to the cathode of lithium ion battery quick charge, including cathode, the cathode is placed in an external electric field.
The cathode is carbon material or silicon materials.Preferably, the carbon material is appointing in graphite, graphene and porous carbonIt is a kind of.
The external electric field is uniform electric field.
The external electric field is obtained by two parallel electric field pole pieces.
Conducive to the preparation method of the cathode of lithium ion battery quick charge, i.e., the cathode of lithium ion battery is applied outside oneElectric field.The external electric field is the uniform electric field generated by two parallel electric field pole pieces.
The outermost electron energy level of cathode carbon atom is improved into 2~3eV under the External Electrical Field.
A kind of lithium ion battery of quick charge including anode, electrolyte and diaphragm, further includes fast conducive to lithium ion batteryThe cathode of speed charging.
The positive electrode that existing lithium ion battery uses such as LiCoO2、LiFePo4, ternary material etc., electrolyte usesLiPF6A kind of material, thus current energy conduction of velocity in lithium ion battery is slow, Li+Movement velocity is slower, thus electric currentIt is slow that energy enters cathode, and then charging rate is slow.And to fundamentally improve the charging rate of lithium ion battery, it must improveCurrent energy conduction of velocity and Li+ in anode, electrolyte are moved to the speed of cathode from anode.But current cathodeMaterial is difficult to the impact and destruction bearing to bring after current energy and the raising of Li+ conduction of velocity.Thus it can not realize lithium-ion electricThe charging of pond fast and stable.
For lithium ion battery, current energy is stored between negative electrode of lithium ion battery atom outermost electron, Li+It is embeddedBetween carbon atom, this is based on current energy after the effect of positive electrode and electrolyte, and conduction of velocity reduces so that electricityStream energy stores between outermost electron and electron vacancy, and lithium ion is then embedded between cathode atom.Existing lithiumWhen ion battery charges, charging current conduction of velocity is in 20-300m/s, when charging current speed significantly exceeds this range,Negative electrode of lithium ion battery is difficult to bear impact and destruction that lithium ion battery quick charge is brought, in the current energy of high-speed motionUnder being impacted with Li+, negative electrode of lithium ion battery is unstable or even destroyed.
When by changing anode and/or electrolyte come when improving the conduction of velocity of current energy and lithium ion, this hairIt is bright to apply external electric field using in cathode, improve the bound level of negative material atom outermost electron.Through inventor's repetition testIt obtains：Only the bound level of cathode carbon atom outermost electron need to be promoted 2-3eV, with regard to negative material stored current energy can be metAmount bears to impact caused by fast current, realizes the effect of quick charge, and also retain lithium ion battery energy densityHigh characteristic.
If the bound level promotion of cathode carbon atom outermost electron is excessively high, temperature rise is excessively high, and then carbon atom mistakeIn " growing up ", it can cause cathode expansion is big to be even damaged, but bound level is too low, storage electricity can be reduced.
Compared with prior art, the present invention it has the following advantages and advantages：
The present invention is conducive to the cathode of lithium ion battery quick charge, when by changing lithium ion cell positive and/or electrolysisMaterial is come when improving the conduction of velocity of current energy and lithium ion, in cathode application external electric field, raising negative material atom is mostThe bound level of cathode carbon atom outermost electron need to only be promoted 2-3eV, with regard to that can meet cathode by the bound level of outer-shell electronAtom stored current energy bears to impact caused by fast current, realizes the effect of quick charge, and also retain lithium fromThe high characteristic of sub- battery energy density.
Description of the drawings
Attached drawing described herein is used for providing further understanding the embodiment of the present invention, forms one of the applicationPoint, do not form the restriction to the embodiment of the present invention.In the accompanying drawings：
Fig. 1 is the lithium ion battery schematic diagram of quick charge of the present invention；
Fig. 2 is the cathode schematic diagram that the present invention is conducive to lithium ion battery quick charge；
Fig. 3 is combined schematic diagram for super capacitance cell with lithium ion battery.
Label and corresponding parts title in attached drawing：
1- anodes, 2- electrolyte, 3- diaphragms, 4- cathode, 5- electric field pole pieces, 6- super capacitors, 7- lithium battery anodes, 8- lithiumsBattery cathode.
Specific embodiment
To make the objectives, technical solutions, and advantages of the present invention clearer, with reference to embodiment and attached drawing, to thisInvention is described in further detail, and exemplary embodiment of the invention and its explanation are only used for explaining the present invention, do not makeFor limitation of the invention.
Embodiment 1
As shown in Figure 1, 2, a kind of lithium ion battery of quick charge including anode 1, electrolyte 2 and diaphragm 3, further includesConducive to the cathode of lithium ion battery quick charge.
Wherein, the cathode conducive to lithium ion battery quick charge is made by the following method：
(1) apply an external electric field outside the cathode of lithium ion battery 4, external electric field is forms by two electric field pole pieces 5Uniform electric field；
(2) the outermost electron bound level of cathode carbon atom is improved into 2~3eV under the action of an external electric field.
Negative material is carbon material or silicon materials, preferably any one of graphite, graphene and porous carbon.
Embodiment 2
As shown in Figure 1, 2, the present embodiment is by taking electric automobile power battery as an example, a kind of lithium ion battery of quick charge,1 material of anode is Li2TiO3, 2 material of electrolyte is LiNiS2, 4 material of cathode is graphite, and diaphragm 3 uses and 4 graphite of cathodeThe PP/PE/PP three-layer membranes matched.
As electric automobile power battery, cathode 4 is energy storage material, and 4 appearance and size of cathode is 1m × 0.1m × 0.1m, bodyProduct is 0.01m3, the electricity that can theoretically store is 6.9 × 109Coulomb, it is about 6.9 × 10 that can actually store electricity7, fillWhen electric, charging voltage U1For 2.0V-2.5V, present 4 both sides of cathode apply an external electric field, and external electric field is uniform electric field, dispatch from foreign news agencyField parameters are as follows：
Voltage of electric field U：23.67V-24.50V；
Direction of an electric field：It is consistent with charging current direction；
Electric field strength：E=236.7V/m；
Test charge temperature：297K-353K.
External electric field is generated by two parallel electric field pole pieces 5, electric field pole chip size be 1m × 0.1m, electric field pole piece 5 withCathode 4 insulate, and for External Electrical Field after cathode 4,4 carbon atom outermost electron energy level of cathode improves 2~2.1eV, is equivalent toCarbon atom temperature reaches 411K, thus cathode graphite carbon atom can bear the impact and destruction that quick charge is brought, and chargeCheng Zhong, electric field strength remain unchanged, and charging time 18min, charge volume, which reaches, can actually store the 95% of electricity, chargeExternal electric field is closed after finishing, discharge process is also without external electric field.
Embodiment 3
As shown in Figure 1, 2, a kind of lithium ion battery of quick charge of the present embodiment, 1 material of anode are LiFeS2, electrolyte2 materials are LiNiS2, 4 material of cathode is graphene, and diaphragm 3 uses and the matched PP/PE/PP three-layer membranes of 4 graphene of cathode.
As general lithium ion battery, cathode 4 is energy storage material, and 4 appearance and size of cathode is 0.1m × 0.1m × 0.1m,Volume is 0.001m3, it is about 6.9 × 10 that can actually store electricity6, during charging, charging voltage U1For 1.8V-2.2V, exist now4 both sides of cathode apply an external electric field, and external electric field is uniform electric field, and external electric field parameters are as follows：
Voltage of electric field U：23.67V-24.50V；
Direction of an electric field：It is consistent with charging current direction；
Electric field strength：E=236.7V/m；
Test charge temperature：297K-353K.
External electric field is generated by two parallel electric field pole pieces 5, electric field pole chip size be 0.1m × 0.1m, electric field pole piece 5It insulate with cathode 4, External Electrical Field is after cathode 4, and 4 carbon atom outermost electron energy level of cathode improves 2~2.1eV, quiteReach 411K in carbon atom temperature, thus cathode graphite carbon atom can bear the impact and destruction that quick charge is brought, chargingIn the process, electric field strength remains unchanged, charging time 8min, and charge volume, which reaches, can actually store the 95% of electricity, chargingAfter close external electric field, discharge process is also without external electric field.
Embodiment 4
A kind of lithium ion battery of quick charge of the present embodiment, 1 material of anode are LiFeS2, 2 material of electrolyte isLiNiS2, 4 material of cathode is graphene, and diaphragm 3 uses and the matched PP/PE/PP three-layer membranes of 4 graphene of cathode.
As lithium ion battery, cathode 4 is energy storage material, and 4 appearance and size of cathode is 0.1m × 0.1m × 0.1m, and volume is0.001m3, it is about 6.9 × 10 that can actually store electricity6, during charging, charging voltage U1For 1.8V-2.2V, charging 120 pointsZhong Hou, lithium ion battery charging does not reach requirement still, and it is hot to start part.
Embodiment 5
As shown in Figure 1, 2, a kind of lithium ion battery of quick charge of the present embodiment, 1 material of anode are LiFeS2, electrolyte2 materials are LiNiS2, 4 material of cathode is graphite, and diaphragm 3 uses and the matched PP/PE/PP three-layer membranes of 4 graphite of cathode.
As lithium ion battery, cathode 4 is energy storage material, and 4 appearance and size of cathode is 0.1m × 0.1m × 0.1m, and volume is0.001m3, it is about 6.9 × 10 that can actually store electricity6, during charging, charging voltage U1For 1.8V-2.2V, now in cathode 4Both sides apply an external electric field, and external electric field is uniform electric field, and external electric field parameters are as follows：
Voltage of electric field U：20.00V-21.50V；
Direction of an electric field：It is consistent with charging current direction；
Electric field strength：E=210V/m；
Test charge temperature：297K-353K.
External electric field is generated by two parallel electric field pole pieces 5, electric field pole chip size be 0.1m × 0.1m, electric field pole piece 5It insulate with cathode 4, for External Electrical Field after cathode 4,4 carbon atom outermost electron energy level of cathode improves 1.5~1.6eV, phaseWhen reaching 390K in carbon atom temperature, cathode graphite carbon atom bears the impact that quick charge brings and the energy of destruction is insufficient,In charging process, electric field strength remains unchanged, and after the charging time is 150min, lithium ion battery charge volume, which reaches, can actually store upThe 65% of electricity is deposited, and charge volume can not continue to increase with the promotion in charging time.
To sum up, the negative electrode of lithium ion battery in embodiment 1-3 can bear the impact and destruction that quick charge is brought, thereforeLithium ion battery has the advantages that charging rate is fast, safe.In embodiment 4, do not apply electric field in negative electrode of lithium ion battery,Therefore when anode and/or electrolyte use being capable of the amount of allowing current to and Li+During the material of high-speed mobile, lithium ion battery can fill notIt is hot to power on even part.In embodiment 5, a uniform electric field is applied with outside negative electrode of lithium ion battery, but due to electric-field strengthIt spends unreasonable, the energy level of cathode carbon atom is caused to be promoted insufficient, therefore charging rate and charge volume substantially reduce, and lead to lithiumIon battery cathode generates fever phenomenon.
Fig. 3 is the schematic diagram that super capacitance cell is combined with lithium ion battery, accordingly it is found that super capacitance cell and lithiumThe product that ion battery is combined is to share cathode and voltage, and wherein super capacitor is used to store electric energy.
The super capacitance cell studied at present, 30s, that is, chargeable are finished, energy density very little, although its momentPower density is big, however the gross energy very little stored, can not meet the power demand of lasting efficient discharge.Super capacitance cell isBe combined by capacitance with lithium ion battery, the two shares cathode, charging rate be the effect that super capacitance cell is brought soon andIn itself, super capacitance cell power density is big for non-lithium battery, and for starting, lithium ion battery energy density is big, for continuing a journey, fillsThe electric time is actually also divided into two parts, and the charging time of lithium ion battery part is still longer, and super capacitance cellIt is also only a kind of indignant thought to be combined with lithium ion battery, technically realizes that difficulty is very big.
Above-described specific embodiment has carried out the purpose of the present invention, technical solution and advantageous effect furtherIt is described in detail, it should be understood that the foregoing is merely the specific embodiment of the present invention, is not intended to limit the present inventionProtection domain, all within the spirits and principles of the present invention, any modification, equivalent substitution, improvement and etc. done should all includeWithin protection scope of the present invention.