A kind of polymer composite solid electrolyte and its preparation method and application
Technical field
The present invention relates to electrochemical energy storage field, more particularly to a kind of polymer composite solid electrolyte and preparation method thereof
And application.
Background technology
Lithium-sulfur cell is one kind using lithium metal as cathode, and sulphurous materials are as positive secondary cell.The reason of lithium metal
It is 3861mAh/g by specific capacity, the theoretical specific capacity of sulphur simple substance reaches 1675mAh/g, to make the theoretical energy of lithium-sulfur cell
Density is up to 2600Wh/kg.Simultaneously in lithium-sulfur cell, element sulphur rich reserves are cheap, with the advantages such as environmental-friendly, tool
There are very big application prospect and Development volue.But meanwhile sulphur simple substance is a kind of electronic body at room temperature, and it is a kind of from
Electronic insulators, directly use sulphur simple substance as it is positive can not be formed can charge and discharge lithium-sulfur cell.Simultaneously in lithium-sulfur cell charge and discharge
In electric process, sulphur can form more lithium sulfides with lithium, and a kind of intermediate product being soluble in electrolyte solution generates " shuttle effect ",
Cause active material largely to lose, and deposited in the lithium an- ode of battery, reduces lithium-sulfur cell cycle life.In addition lithium sulphur electricity
The final product of tank discharge, lithium sulfide compare the enlarged volume 70-80% of sulphur simple substance, anode can be caused to be destroyed, and reduce cycle
Service life.In addition, it has been found that in all solid state battery structure, contact of the solid with solid can prevent electrode in lithium-sulfur cell
Reaction is formed by the dissolving of polysulfide, but in existing lithium-sulfur cell system, the matching of electrolyte and battery is still
There are problems that, it is therefore desirable to find a kind of new lithium-sulfur cell system, further increase the cycle performance of battery.
Invention content
For the problem present on, the present invention provides a kind of polymer composite solid electrolytes, as lithium sulphur
The polymer composite solid electrolyte of battery, and this polymer composite solid electrolyte and carbon black and sulphur simple substance are fabricated to again
Sulfur electrode material is closed, to form new lithium-sulfur cell system.It is above to improve, it improves the specific discharge capacity of lithium-sulfur cell and follows
The ring service life.
Technical scheme is as follows:
A kind of polymer composite solid electrolyte is made of polyphenylene sulfide, lithium salts and organic quinones electron acceptor;
The quinones electron acceptor is preferably dichlorodicyanobenzoquinone, chloranil, and tetracyanoquinodimethane is described
Lithium salts is lithium hydroxide and/or lithium carbonate;The mass ratio of the polyphenylene sulfide, lithium salts and organic quinones electron acceptor is 100:
15-50:40-80.
The preparation method of the polymer composite solid electrolyte is as follows:
(1) polyphenylene sulfide particle is mixed with lithium salts;
(2) organic quinones electron acceptor is added into said mixture, the oil base quinones electron acceptor;
Then mixture is placed in sealing reaction kettle and is reacted, room temperature is then cooled to, obtains polymer composite solid
State electrolyte.
The lithium salts is lithium hydroxide and/or lithium carbonate;
Polyphenylene sulfide described in step (1) is 100 with the mass ratio of lithium hydroxide and/or lithium carbonate:(15-50);It is described
Mixing is to use airflow milling that grain size is made as 0.5-2 μm of powder in mixture, and mixing is abundant.
The mass ratio of polyphenylene sulfide described in step (2) and organic quinones electron acceptor is 100:(40-80).The reaction
The reaction condition of kettle is that temperature is 200-350 DEG C, and the time is 0.5-2 hours.
The conductive black is acetylene black, heavy oil furnace black, gas making product carbon etc..
Organic quinones electron acceptor is preferably dichlorodicyanobenzoquinone (DDQ), chloranil (p-chloranil),
Tetracyanoquinodimethane (TCNQ).
The present invention also provides a kind of sulphur combination electrode materials, and polymer composite solid electrolyte and conductive black are coated sulphur
The sulphur combination electrode material of formation.
The preparation method of the sulphur combination electrode material, includes the following steps:
(1) the polymer composite solid electrolyte is milled to fine grained, by thin of polymer composite solid electrolyte
Grain is uniformly mixed with sulphur simple substance and conductive black, obtains mixture;
(2) then the mixture that step (1) obtains being placed in sealing reaction kettle, heating makes sulphur be in melting state, and
It is adsorbed by conductive black and polymer composite solid electrolyte, is electrolysed by conductive black and polymer composite solid to obtain
The conduction that matter is coated with sulphur leads lithium ion network, forms the sulphur combination electrode material containing polymer composite solid electrolyte.
The polymer composite solid electrolyte particle is the grain size that 1-10 μm is crushed to airflow milling.
The polymer composite solid electrolyte, sulphur simple substance, conductive black mass ratio be 10-20:50-70:15-
25, the reaction condition is 100-250 DEG C of temperature, keeps the temperature 2-6 hours.
Further, lithium-sulphur cell positive electrode piece is made in the sulphur combination electrode material, steps are as follows:
The sulphur combination electrode material is milled to fine grained, it is 0.5-2 μm of powder to be ground into grain size followed in turn by airflow milling
This powder is positioned on hot press by end, and 400-600PSI pressure is imposed at 80-150 DEG C and is pressed into 200-300 μ m-thick sheet materials,
Form lithium-sulfur cell sulphur positive plate.
Further, the lithium-sulphur cell positive electrode piece also can be prepared as follows:
By the sulphur combination electrode material grind into powder, the methyl pyrrole with pre-configured Kynoar (PVDF)
Pyrrolidone (NMP) solution mixes, and is stirred into slurry;Then slurry is coated in film applicator on 10-20 μm of aluminium foil.It will coat
Aluminium foil be positioned in vacuum drying oven, in 50-80 DEG C of vacuum drying 4-8 hours, NMP is removed, it is afflux to be made with aluminium foil
The lithium-sulphur cell positive electrode piece of body.
The present invention also provides a kind of lithium-sulfur cell, including anode, cathode and polymer composite solid electrolyte, the anode
It is made of sulphur combination electrode material, the cathode is lithium metal or lithium alloy.
The beneficial effects of the invention are as follows:The present invention provides a kind of polymer composite solid electrolytes, by lithium salts, macromolecule
Compound PPS and organic quinones electron acceptor composition, PPS with conjugated main chain and sulphur atom with lone pair electrons, and it is organic
Quinones electron acceptor interacts, while organic quinones electron acceptor interacts with lithium ion again, forms orphan.
To make the polymer composite solid electrolyte that there is flame retardant effect, and exist largely for lithium ion transition in electrolyte
Point has higher conductivity at room temperature.In the positive electrode made of the polymer composite solid electrolyte due to
Polymer composite solid electrolyte and acetylene black uniform adsorption sulphur, form good conduction and lead lithium ion network, to sulphur and
The more lithium sulfides of intermediate product in charge and discharge process are fixed, it is suppressed that " shuttle effect ".Polymer composite solid simultaneously
The toughness and rigidity that electrolyte has can also inhibit the volume change in charge and discharge process, promote sulphur positive-plate life.High score simultaneously
Sub- polymer composite solid electrolyte provides preferable lithium ion mobility channel, improves the lithium-ion electric of composite positive pole
Conductance.High molecular polymer composite solid electrolyte has certain rigidity and toughness, after having buffered lithium-sulfur cell charge and discharge, just
The volume change of pole.To promote the cycle life and specific capacity of lithium-sulfur cell.After tested, the battery prepared using the present invention can
Can still keep the sulphur active material specific capacity of 800mAh/g after the cycle at 500 times.
Description of the drawings
The present invention includes the following drawings, and shown content is respectively:
Fig. 1 is the constant current charge-discharge circulation volume curve of lithium-sulfur cell made from embodiment 1;
Fig. 2 is the constant current charge-discharge circulation volume curve of lithium-sulfur cell made from embodiment 3;
Fig. 3 is the conductivity variation with temperature curve of polymer composite solid electrolyte made from embodiment 1.
Specific implementation mode
By the description of embodiment, the specific implementation mode of invention is described in further detail, it is therefore an objective to help this
The technical staff in field has more complete, accurate and deep understanding, and contributes in fact to the design of the present invention, technical solution
It applies.
Embodiment 1
The preparation of polymer composite solid electrolyte
By polyphenylene sulfide (PPS) particle and lithium hydroxide (LiOH) and lithium carbonate (Li2CO3) according to mass ratio 100:16:16
It is mixed, grain size then, which is made, in mixture by airflow milling is less than 1 μm of powder.According to polyphenylene sulfide and dichlorodicyanobenzoquinone
Mass ratio is 100:50 add dichlorodicyanobenzoquinone (DDQ) into said mixture.Mixture is then placed in sealing reaction kettle
In.It is heated to 260 DEG C and keeps the temperature 1 hour, be then cooled to room temperature, obtain polymer composite solid electrolyte, the polymer is compound
The conductivity of solid electrolyte sees table 1.
The preparation of sulphur combination electrode material
Above-mentioned polymer composite solid electrolyte is taken out from reaction kettle, and is milled to fine grained, followed in turn by air-flow
Polymer composite solid electrolyte is crushed to 1 μm of grain size by mill.By polymer composite solid electrolyte fine grained and sulphur simple substance, second
Acetylene black is with 16:64:16 mass ratios uniformly mix.Then mixture is placed in sealing reaction kettle, is heated to 155 DEG C of heat preservations 4
Hour, so that sulphur is in melting state, and adsorbed by acetylene black and polymer composite solid electrolyte.To obtain by acetylene black
The conduction that sulphur is coated with polymer composite solid electrolyte leads lithium ion network, is formed and contains polymer composite solid electrolyte
Sulphur combination electrode material.
The preparation of lithium-sulphur cell positive electrode piece
The above-mentioned sulphur combination electrode material containing polymer composite solid electrolyte is taken out from reaction kettle, and is milled to
Fine grained is crushed to 1 μm of diameter powders followed in turn by airflow milling.This powder is positioned on hot press, is imposed at 100 DEG C
500PSI pressure keeps being pressed within 5 minutes 200 μ m-thick sheet materials, forms lithium-sulfur cell sulphur positive plate.
Lithium-sulfur cell
Using above-mentioned lithium-sulphur cell positive electrode piece as anode, using lithium metal as cathode, with above-mentioned polymer composite solid electricity
Solution matter is that lithium-sulfur cell is made in electrolyte.
Fig. 1 is the constant current charge-discharge circulation volume curve of lithium-sulfur cell prepared by embodiment 1.The initial discharge of the battery is held
Amount, sulphur specific capacity are higher than 1000mAh/g.After cycle 500 times, the sulphur specific capacity in the battery has still reached 800mAh/
g.The rate of decay is very slow after battery capacity stabilization, has sufficiently high specific capacity and practicability.
Embodiment 2
The preparation of polymer composite solid electrolyte
By polyphenylene sulfide (PPS) particle and lithium hydroxide (LiOH) according to mass ratio 100:30 are mixed, and are then passed through
Mixture is made grain size and is less than 0.5 μm of powder by airflow milling.According to polyphenylene sulfide and the mass ratio of chloranil 100:40 to
Chloranil is added in said mixture, and then mixture is placed in sealing reaction kettle.It is heated to 210 DEG C and keeps the temperature 2 hours,
It is then cooled to room temperature, obtains polymer composite solid electrolyte, the conductivity of the polymer composite solid electrolyte sees table
1。
The preparation of sulphur combination electrode material
Above-mentioned polymer composite solid electrolyte is taken out from reaction kettle, and is milled to fine grained, followed in turn by air-flow
Polymer composite solid electrolyte is crushed to 2 μm of grain sizes by mill.By polymer composite solid electrolyte fine grained and sulphur simple substance, second
Acetylene black is with 10:50:15 mass ratios uniformly mix.Then mixture is placed in sealing reaction kettle, is heated to 200 DEG C of heat preservations 6
Hour, so that sulphur is in melting state, and adsorbed by acetylene black and polymer composite solid electrolyte.To obtain by acetylene black
The conduction that sulphur is coated with polymer composite solid electrolyte leads lithium ion network.It is formed and contains polymer composite solid electrolyte
Sulphur combination electrode material.
The preparation of lithium-sulphur cell positive electrode piece
The above-mentioned sulphur combination electrode material containing polymer composite solid electrolyte is taken out from reaction kettle, and is milled to
Fine grained is crushed to 2 μm of diameter powders followed in turn by airflow milling.This powder is positioned on hot press, is imposed at 80 DEG C
400PSI pressure keeps being pressed within 5 minutes 250 μ m-thick sheet materials, forms lithium-sulfur cell sulphur positive plate.
Lithium-sulfur cell
Using above-mentioned lithium-sulphur cell positive electrode piece as anode, using lithium metal as cathode, with above-mentioned polymer composite solid electricity
Solution matter is that lithium-sulfur cell is made in electrolyte.
Embodiment 3
The preparation of polymer composite solid electrolyte
By polyphenylene sulfide (PPS) particle and lithium hydroxide (LiOH) according to mass ratio 100:50 are mixed, and are then passed through
0.5 μm of powder of grain size is made in mixture by airflow milling.It is 100 according to polyphenylene sulfide and tetracyanoquinodimethane mass ratio:
60 add tetracyanoquinodimethane into said mixture.Then mixture is placed in sealing reaction kettle.It is heated to 300
DEG C heat preservation 0.5 hour, is then cooled to room temperature, obtains polymer composite solid electrolyte, the polymer composite solid electrolyte
Conductivity see table 1.
The preparation of sulphur combination electrode material
Above-mentioned polymer composite solid electrolyte is taken out from reaction kettle, and is milled to fine grained, followed in turn by air-flow
Polymer composite solid electrolyte is crushed to 1 μm of grain size by mill.By polymer composite solid electrolyte fine grained and sulphur simple substance, second
Acetylene black is with 20:70:16 uniformly mixing.Then mixture is placed in sealing reaction kettle, 250 DEG C is heated to and keeps the temperature 2 hours, make sulphur
It is adsorbed in melting state, and by acetylene black and polymer composite solid electrolyte.To obtain by acetylene black and polymer
The conduction that composite solid electrolyte is coated with sulphur leads lithium ion network.It is compound to form the sulphur containing polymer composite solid electrolyte
Electrode material.
The preparation of lithium-sulphur cell positive electrode piece
According to mass ratio it is 1 by Kynoar (PVDF) and methyl pyrrolidone (NMP):20 are configured to solution mixing,
According to sulphur combination electrode material powder and PVDF 96:Sulphur combination electrode material powder is added in 4 mass ratio, stirs evenly and is slurried
Material.Then slurry is coated in film applicator on 15 μm of aluminium foils.The aluminium foil coated is positioned in vacuum drying oven, is dried in 60 DEG C of vacuum
It is 6 hours dry, NMP is removed, is made with the lithium-sulphur cell positive electrode piece that aluminium foil is collector.
Lithium-sulfur cell
Using above-mentioned lithium-sulphur cell positive electrode piece as anode, using lithium metal as cathode, with above-mentioned polymer composite solid electricity
Solution matter is that lithium-sulfur cell is made in electrolyte.
Fig. 2 is the constant current charge-discharge circulation volume curve of lithium-sulfur cell prepared by embodiment 3.The initial discharge sulphur of the battery
Specific capacity is higher than 1000mAh/g.After cycle 500 times, the sulphur specific capacity in the battery has still reached 800mAh/g.Battery
Overall attenuation speed is extremely slow, and the service life has reached 500 times, has sufficiently high specific capacity and practicability.
Embodiment 4-10
Polymer composite solid electrolyte is prepared according to the step of embodiment 1, wherein only each component dosage is different, other steps
Rapid identical, the usage variance of each substance sees table 1, and the conductivity of polymer composite solid electrolyte obtained sees table 1.
Embodiment 11
Polymer composite solid electrolyte prepared by embodiment 1 DEG C becomes with 10 DEG C for interval from -50 DEG C to 110 with temperature
The conductivity of change.By can see in Fig. 3, conductivity is rising with temperature rise.At low temperatures, -40 DEG C, the polymer
Composite solid electrolyte conductivity is 1 × 10-4S/cm, 20 DEG C at room temperature, which is 3
×10-4S/cm.The polymer composite solid electrolyte has higher conductivity within the scope of wide temperature and has no apparent
Conductivity mutation.
Table 1:The conductivity of polymer composite solid electrolyte made from embodiment 1-10