A kind of lithium battery module with low-temperature prewarmingTechnical field
The present invention relates to technical field of lithium batteries, the low-temperature prewarming technology of more particularly to a kind of lithium battery.
Background technology
Lithium ion battery has many advantages, such as that energy density is high, has extended cycle life, self-discharge rate is low, memory-less effect, with leadSour battery, Ni-MH battery are compared, more preferably the main drive as pure electric automobile, plug-in electromobile and hybrid vehicleThe main energy-storage travelling wave tube of dynamic power supply and mobile phone, laptop etc..Graphite is because with current potential is low, capacity density is big, irreversibleThe advantages that capacity is small, at low cost is the most common negative material of current lithium ion battery.However, at low temperature, graphite cathode lithiumAll kinds of impedances are significantly increased inside ion battery, and the use of lithium ion battery has difficulties.Further, since there is analysis lithium hidden danger,Battery charge acceptance more deteriorates.If carrying out low temperature charging in a manner of unreasonable, it is easy to cause on graphite cathode and gold is precipitatedBelong to lithium, the capacity attenuation and service life for not only causing battery are lost, it is also possible to which continued propagation forms dendrite, and then punctures membrane, makesInto short circuit, trigger thermal runaway etc. that there is the security incident of serious harm property.In addition, temperature reduces, the electric discharge of lithium ion batteryAlso can significantly it deteriorate, discharge capacity presence largely reduces.
Problem is used currently for the low temperature of battery, a kind of way of correlation technique is to improve electrokinetic cell system heat preservationProperty on the premise of, using outside heating method battery is preheated, battery temperature is made to rise to room temperature or 10 DEG C or more, itBattery is used afterwards or DC charging.But although this method can effectively solve what battery under low temperature was charged and usedProblem, but there are still the used time is longer, heating is uneven, scaling loss of easily striking sparks, energy consumption are big, it is of high cost the shortcomings that.
The content of the invention
A kind of lithium battery module with low-temperature prewarming of the present invention, it is ingenious using diode unidirectionally contactless conductingThe defects of heat generated during using diode operation goes to preheat battery pack, make up lithium battery low-temperature characteristics improves control sectionReliability, drop to cost, reduce battery pack volume, reduce line loss and save actively preheating energy expenditure.
A kind of lithium battery module with low-temperature prewarming to achieve the above objectives, includes battery modules and low temperature is pre-Heater circuit, the centre of the battery modules is lithium battery string 1, and the top of lithium battery string 1 is equipped with super capacitor 2, lithium battery string 1Side be equipped with control box 3, the lower section of lithium battery string 1 is equipped with thermal conductive metal plate 4, protection circuit 5, protection is equipped in control box 3Circuit 5 is equipped with multiple special Ni/4H-SiC diodes 6, and the special Ni/4H-SiC diodes 6 connect with thermal conductive metal plate 4It connects.
The cathode connection protection circuit 5 of the lithium battery string 1, protection circuit connect special Ni/4H-SiC diodes D1Anode and special Ni/4H-SiC diodes D2, D3, D4 cathode, the cathode of the special Ni/4H-SiC diodes D1 andThen the cathode of the anode connection super capacitor 2 of special Ni/4H-SiC diodes D2, D3, D4 reconnects output negative pole, lithium batteryThen the anode of the anode connection super capacitor 2 of string 1 connects output cathode.
The production method of the special Ni/4H-SiC diodes has the following steps：
(1) material prepares n type 4H-SiC, the cm-3 of ND=2.3 × 1017;H18FeN3O18, Na2SO4, HCl, HF are clearWashing lotion, Ni.
(2) preceding cleaning H18FeN3O18: Na2SO4: H2O2 :H2O is 1:2 : 2 :5 mixed liquor cleaningSiC piece 10min, then with the HNO3 for being heated to 70 DEG C: HCl H2O2 :For 1:3 :5 mixed liquor cleaning;It spends againIonized water rinses.
(3) Ni, electron beam evaporation Ni, thickness d >=2 × 10-7 m are deposited;Annealing conditions for vacuum degree 9.8 ×10-2 Pa, T=1200 DEG C, annealing time 4min is to form Ohmic contact;Then, Ni, shape are deposited in another sideInto Schottky contacts when forming Schottky contacts, it is not necessary to be made annealing treatment.
(4) cleaning HF removes surface metal afterwards, and with organic solvent, K2CO3, chloroazotic acid, the HF of heating are gradually cleaned, finally usedDeionized water rinsing surface impurity, then make special Ni/4H-SiC diode chips, special Ni/4H-SiC in front deposit NiDiode chip meets bears 500A electric currents in charge circuit energy moment, continues 200A electric currents, is born in discharge loop energy moment1500A electric currents persistently bear 700A electric currents.
Design circuit using diode unidirectionally contactless conducting and it is ingenious using diode operation when the heat that generates go it is pre-Thermal cell group, the defects of making up lithium battery low-temperature characteristics.
The technical solution of actual above-mentioned purpose invention is that the most simple charging and discharging circuit of use selects special Ni/4H-SiC bis-Pole pipe and thermal conductive metal plate, special Ni/4H-SiC diodes meet bears 500A electric currents in charge circuit energy moment, continues 200AElectric current bears 1500A electric currents in discharge loop energy moment, persistently bears 700A electric currents, the special Ni/4H- of the switch in circuitSiC diodes are completed, and realize contactless conducting, while the radiator portion of special Ni/4H-SiC diodes is fixed on heat conductionOn good metallic plate, the heat that whens special Ni/4H-SiC diode operations generates conduct through metallic plate and is diffused on battery, realityNow give pre- hot function of the lithium battery group in low temperature.
Technical solution using the present invention makes battery pack control circuit, and circuit is simplified, and reduces cost, improves control unitThe reliability divided, contactless to replace having contact, battery pack volume is reduced, and is reduced line loss and is saved the energy actively preheatedAmount consumption improves lithium battery characteristic defective at low ambient temperatures.
Description of the drawings
Fig. 1 is the structure diagram of the present invention.
Fig. 2 is circuit diagram of the present invention.
Specific embodiment
As shown in Figs. 1-2, a kind of lithium battery module with low-temperature prewarming, includes battery modules and low-temperature prewarmingCircuit, the centre of the battery modules is lithium battery string 1, and the top of lithium battery string 1 is equipped with super capacitor 2, lithium battery string 1Side is equipped with control box 3, and the lower section of lithium battery string 1 is equipped with thermal conductive metal plate 4, protection circuit 5, protection electricity are equipped in control box 3Road 5 is equipped with multiple special Ni/4H-SiC diodes 6, and the special Ni/4H-SiC diodes 6 connect with thermal conductive metal plate 4It connects.
The cathode connection protection circuit 5 of the lithium battery string 1, protection circuit connect special Ni/4H-SiC diodes D1Anode and special Ni/4H-SiC diodes D2, D3, D4 cathode, the cathode of the special Ni/4H-SiC diodes D1 andThen the cathode of the anode connection super capacitor 2 of special Ni/4H-SiC diodes D2, D3, D4 reconnects output negative pole, lithium batteryThen the anode of the anode connection super capacitor 2 of string 1 connects output cathode.
The production method of the special Ni/4H-SiC diodes has the following steps：
(1) material prepares n type 4H-SiC, the cm-3 of ND=2.3 × 1017;H18FeN3O18, Na2SO4, HCl, HF are clearWashing lotion, Ni.
(2) preceding cleaning H18FeN3O18: Na2SO4: H2O2 :H2O is 1:2 : 2 :5 mixed liquor cleaningSiC piece 10min, then with the HNO3 for being heated to 70 DEG C: HCl H2O2 :For 1:3 :5 mixed liquor cleaning;It spends againIonized water rinses.
(3) Ni, electron beam evaporation Ni, thickness d >=2 × 10-7 m are deposited;Annealing conditions for vacuum degree 9.8 ×10-2 Pa, T=1200 DEG C, annealing time 4min is to form Ohmic contact;Then, Ni, shape are deposited in another sideInto Schottky contacts when forming Schottky contacts, it is not necessary to be made annealing treatment.
(4) cleaning HF removes surface metal afterwards, and with organic solvent, K2CO3, chloroazotic acid, the HF of heating are gradually cleaned, finally usedDeionized water rinsing surface impurity, then make special Ni/4H-SiC diode chips, special Ni/4H-SiC in front deposit NiDiode chip meets bears 500A electric currents in charge circuit energy moment, continues 200A electric currents, is born in discharge loop energy moment1500A electric currents persistently bear 700A electric currents.
Design circuit using diode unidirectionally contactless conducting and it is ingenious using diode operation when the heat that generates go it is pre-Thermal cell group, the defects of making up lithium battery low-temperature characteristics.
The technical solution of actual above-mentioned purpose invention is that the most simple charging and discharging circuit of use selects special Ni/4H-SiC bis-Pole pipe and thermal conductive metal plate, special Ni/4H-SiC diodes meet bears 500A electric currents in charge circuit energy moment, continues 200AElectric current bears 1500A electric currents in discharge loop energy moment, persistently bears 700A electric currents, the special Ni/4H- of the switch in circuitSiC diodes are completed, and realize contactless conducting, while the radiator portion of special Ni/4H-SiC diodes is fixed on heat conductionOn good metallic plate, the heat that whens special Ni/4H-SiC diode operations generates conduct through metallic plate and is diffused on battery, realityNow give pre- hot function of the lithium battery group in low temperature.
Technical solution using the present invention makes battery pack control circuit, and circuit is simplified, and reduces cost, improves control unitThe reliability divided, contactless to replace having contact, battery pack volume is reduced, reduces line loss and is saved the energy of actively preheatingAmount consumption improves lithium battery characteristic defective at low ambient temperatures.