阅读说明：本技术 一种热电池单体电池及其制备方法 (A kind of single cell of thermo battery and preparation method thereof ) 是由 曹勇 刘效疆 王超 董亮平 杨潇薇 于 2019-09-11 设计创作，主要内容包括：本发明公开了一种热电池单体电池及其制备方法,属于热电池技术领域。本发明通过在热电池单体电池设计及制备过程中提高正极中Li<Sup>+</Sup>盐浓度,同时相应减少负极或电解质中Li<Sup>+</Sup>熔盐的浓度,延缓放电过程正极中Li<Sup>+</Sup>浓度显著下降而引起电化学极化阻抗的增大和熔盐成分偏析而引起的电解质凝固。本发明能够实现热电池放电性能的明显提升,具有广阔的应用前景和现实意义。(The invention discloses a kind of single cell of thermo battery and preparation method thereof, belong to thermal cell technical field.The present invention is by improving Li in anode in single cell of thermo battery design and preparation process + Salinity, while Li in corresponding reduction cathode or electrolyte + The concentration of fused salt delays Li in discharge process anode + Concentration is remarkably decreased and causes electrolyte coagulation caused by the increase and molten salt composition segregation of activation polarization impedance.The present invention can be realized being obviously improved for thermal cell discharge performance, have broad application prospects and realistic meaning.)

1. a kind of preparation method of single cell of thermo battery, which comprises the following steps:

(1) standard fused salt, the lithium ion content for preparing molten salt composition respectively corresponding to lowest total of the melting point are higher than the standard fused salt Poor lithium fused salt of the rich lithium fused salt and lithium ion content of middle lithium ion content lower than lithium ion content in the standard fused salt；

(2) the rich lithium fused salt is mixed with positive electrode active materials, obtains positive electrode；By the poor lithium fused salt or the standard Fused salt is mixed with fused salt flow inhibitor, obtains electrolyte；By the poor lithium fused salt or the standard fused salt and negative electrode active material Material mixing, obtains negative electrode material；

(3) positive electrode, electrolyte and negative electrode material are suppressed by dry pressing, single cell of thermo battery is made.

2. the preparation method of single cell of thermo battery according to claim 1, which is characterized in that in step (1): the richness High 5~the 25wt.% of lithium ion content in lithium ion content relative standard fused salt in lithium fused salt, lithium ion contains in the poor lithium fused salt Measure the low 10~40wt.% of lithium ion content in relative standard's fused salt.

3. the preparation method of single cell of thermo battery according to claim 2, which is characterized in that in step (1): preparation institute It states standard fused salt, the rich lithium fused salt and the poor lithium fused salt to include: by each components of molten salt high-temperature calcination, mix, and in height Congruent melting is carried out at a temperature of fusing point, then chilling, film-making, ball milling and sieving.

4. the preparation method of single cell of thermo battery according to claim 2, which is characterized in that in step (2):

The content of the positive electrode active materials is 70~90wt.% of the positive electrode；

The content of the flow inhibitor is 30~60wt.% of the electrolyte；

The content of the negative electrode active material is 70~95wt.% of the negative electrode material.

5. the preparation method of single cell of thermo battery according to claim 4, which is characterized in that in step (2):

The positive electrode active materials include: CoS₂、FeS₂、Fe_1-xCo_xS₂(0.3≤x≤0.8)、MnO₂、NiCl₂、CuV₂O₆、 Cu₃V₂O₈、V₂O₅、CoF₂、CoF₃、FeF₃、Fe_1-xCo_xF_y(0.3≤x≤0.8,2≤y≤3), CuCl₂、MoO₃And LiV₂O₅In One or more combinations；

The fused salt flow inhibitor includes: MgO, ZrO₂And Al₂O₃One of or multiple combinations；

The negative electrode active material includes: one of LiSi, LiB, LiFe and LiNi or multiple combinations.

6. the preparation method of single cell of thermo battery according to claim 5, which is characterized in that in step (2): preparation institute Stating positive electrode, the electrolyte and the negative electrode material includes: mixing and sieving, and hybrid mode includes three-dimensional blender, ball Mill uses vibrating screen.

7. the preparation method of single cell of thermo battery according to claim 1, which is characterized in that the thermal cell monocell It is LiCl-KCl binary electrolyte thermal cell, wherein the content of LiCl is 50~70wt.% in rich lithium fused salt, in poor lithium fused salt The content of LiCl is 20~40wt.%.

8. the preparation method of single cell of thermo battery according to claim 1, which is characterized in that the thermal cell monocell It is LiCl-LiBr-KBr ternary low melting point electrolyte thermal battery；Wherein, the content of LiCl is 12~25wt.% in rich lithium fused salt, The content of LiBr is 36~62wt.%；The content of LiCl is 0~12wt.% in poor lithium fused salt, the content of LiBr is 20~ 36wt.%.

9. a kind of single cell of thermo battery comprising positive electrode, electrolyte and negative electrode material, which is characterized in that

The positive electrode includes rich lithium fused salt and positive electrode active materials；The electrolyte includes poor lithium fused salt and fused salt flowing suppression Preparation or standard fused salt and fused salt flow inhibitor；The negative electrode material includes poor lithium fused salt and negative electrode active material, or Standard fused salt and negative electrode active material；

Wherein, the standard fused salt is the fused salt that molten salt composition corresponds to lowest total of the melting point, and the richness lithium fused salt is that lithium ion contains Amount is higher than the fused salt of lithium ion content in the standard fused salt, and the poor lithium fused salt is lithium ion content lower than the standard fused salt The fused salt of middle lithium ion content.

10. the preparation method of single cell of thermo battery according to claim 9, which is characterized in that

High 5~the 25wt.% of lithium ion content, the poor lithium fused salt in lithium ion content relative standard's fused salt in the richness lithium fused salt Low 10~the 40wt.% of lithium ion content in middle lithium ion content relative standard fused salt；

The content of the positive electrode active materials is 70~90wt.% of the positive electrode, and the content of the flow inhibitor is 30~60wt.% of the electrolyte, the content of the negative electrode active material are 70~95wt of the negative electrode material.

Technical field

The present invention relates to thermal cell technical fields, and in particular to a kind of single cell of thermo battery and preparation method thereof.

Background technique

Nowadays, the electrolyte being often used in thermal cell includes LiCl-55.2wt.%KCl binary electrolyte, LiCl- 36.5wt.%LiBr-51.4wt.%KBr ternary low melting point electrolyte, the full lithium of LiF-22wt.%LiCl-68.4wt.%LiBr Electrolyte, used ingredient correspond to the lowest total of the melting point of fused salt.Binary electrolyte and the more full lithium of ternary low melting point electrolyte Electrolyte has lower fusing point and operating temperature range, it is made to be used widely in the thermal cell of middle long-life, and difficult With substitution.

Using binary and ternary low melting point as the lithium system thermal cell of electrolyte, during discharge, Li⁺In cathode not medium well At, anode be constantly consumed, lead to Li at anode⁺Concentration is insufficient and retaining ion-electron exchange processes, increases thermal cell electricity Chemical polarization impedance, to reduce battery performance.Meanwhile Li⁺The decline of concentration will lead to the rising of fused salt fusing point, cause battery Failure.Therefore, for using the molten salt system of non-single cation as the thermal cell of electrolyte, molten salt composition segregation can cause thermoelectricity Pond performance is decreased obviously.

Summary of the invention

The object of the present invention is to provide a kind of single cell of thermo battery and preparation method thereof, to solve existing thermal cell because molten The problem of salt component is segregated and thermal cell discharge performance is caused to decline.

The technical scheme to solve the above technical problems is that

A kind of preparation method of single cell of thermo battery, comprising the following steps:

(1) standard fused salt, the lithium ion content for preparing molten salt composition respectively corresponding to lowest total of the melting point are higher than standard fused salt Poor lithium fused salt of the rich lithium fused salt and lithium ion content of middle lithium ion content lower than lithium ion content in standard fused salt；

(2) rich lithium fused salt is mixed with positive electrode active materials, obtains positive electrode；By poor lithium fused salt or standard fused salt and melt The mixing of salt flow inhibitor, obtains electrolyte；Poor lithium fused salt or standard fused salt are mixed with negative electrode active material, obtain cathode material Material；

(3) positive electrode, electrolyte and negative electrode material are suppressed by dry pressing, single cell of thermo battery is made.

Further, in preferred embodiments of the present invention, in step (1): lithium ion content is opposite in rich lithium fused salt marks High 5~the 25wt.% of lithium ion content in quasi- fused salt, lithium ion content is low in lithium ion content relative standard's fused salt in poor lithium fused salt 10~40wt.%.

Preferably, the high 10~20wt.% of lithium ion content, poor lithium in lithium ion content relative standard's fused salt in rich lithium fused salt Low 15~the 30wt.% of lithium ion content in lithium ion content relative standard fused salt in fused salt.

It is highly preferred that the high 15wt.% of lithium ion content, poor lithium are molten in lithium ion content relative standard's fused salt in rich lithium fused salt The low 20wt.% of lithium ion content in lithium ion content relative standard fused salt in salt.

Further, in preferred embodiments of the present invention, in step (1): preparation standard fused salt, rich lithium fused salt and poor lithium Fused salt include: by each components of molten salt high-temperature calcination, mixing, and be higher than fusing point at a temperature of carry out congruent melting, then chilling, system Piece, ball milling and sieving.

Further, in preferred embodiments of the present invention, in step (2): the content of positive electrode active materials is positive material 70~90wt.% of material；The content of flow inhibitor is 30~60wt.% of electrolyte；The content of negative electrode active material is negative 70~95wt.% of pole material.

Preferably, the content of positive electrode active materials is 75~85wt.% of positive electrode；The content of flow inhibitor is electricity Solve 40~50wt.% of matter；The content of negative electrode active material is 75~85wt.% of negative electrode material.

It is highly preferred that the content of positive electrode active materials is the 80wt.% of positive electrode；The content of flow inhibitor is electrolysis The 50wt.% of matter；The content of negative electrode active material is the 80wt.% of negative electrode material.

Further, in preferred embodiments of the present invention, the mass ratio of positive electrode, electrolyte and negative electrode material is (4-6): 4:(5-6).

Preferably, the mass ratio of positive electrode, electrolyte and negative electrode material is 4:4:5.

Preferably, the mass ratio of positive electrode, electrolyte and negative electrode material is 5:4:5.

Preferably, the mass ratio of positive electrode, electrolyte and negative electrode material is 6:4:6.

Preferably, the mass ratio of positive electrode, electrolyte and negative electrode material is 5:4:5.5.

Further, in preferred embodiments of the present invention, in step (2):

Positive electrode active materials include: CoS₂、FeS₂、Fe_1-xCo_xS₂(0.3≤x≤0.8)、MnO₂、NiCl₂、CuV₂O₆、 Cu₃V₂O₈、V₂O₅、CoF₂、CoF₃、FeF₃、Fe_1-xCo_xF_y(0.3≤x≤0.8,2≤y≤3), CuCl₂、MoO₃And LiV₂O₅In One or more combinations；

Fused salt flow inhibitor includes: MgO, ZrO₂And Al₂O₃One of or multiple combinations；

Negative electrode active material includes: one of LiSi, LiB, LiFe and LiNi or multiple combinations.

Further, in preferred embodiments of the present invention, in step (2): preparing positive electrode, electrolyte and cathode material Material includes: mixing and sieving, and hybrid mode includes three-dimensional blender, ball milling or uses vibrating screen.

Further, in preferred embodiments of the present invention, thermal cell monocell is LiCl-KCl binary electrolyte thermoelectricity Pond, wherein the content of LiCl is 50~70wt.% in rich lithium fused salt, and the content of LiCl is 20~40wt.% in poor lithium fused salt.

Preferably, the content of LiCl is 60~70wt.% in the rich lithium fused salt of LiCl-KCl binary electrolyte thermal cell, poor The content of LiCl is 25~35wt.% in lithium fused salt.

It is highly preferred that the content of LiCl is 60wt.%, poor lithium in the rich lithium fused salt of LiCl-KCl binary electrolyte thermal cell The content of LiCl is 35wt.% in fused salt.

Further, in preferred embodiments of the present invention, thermal cell monocell is LiCl-LiBr-KBr ternary low melting point Electrolyte thermal battery；Wherein, the content of LiCl is 12~25wt.% in rich lithium fused salt, and the content of LiBr is 36~62wt.%； The content of LiCl is 0~12wt.% in poor lithium fused salt, and the content of LiBr is 20~36wt.%.

Preferably, the content of LiCl is 15 in the rich lithium fused salt of LiCl-LiBr-KBr ternary low melting point electrolyte thermal battery The content of~20wt.%, LiBr are 45~55wt.%；The content of LiCl is 4~10wt.%, the content of LiBr in poor lithium fused salt For 20~30wt.%.

It is highly preferred that the content of LiCl is in the rich lithium fused salt of LiCl-LiBr-KBr ternary low melting point electrolyte thermal battery The content of 20wt.%, LiBr are 50wt.%；The content of LiCl is 6wt.% in poor lithium fused salt, and the content of LiBr is 24wt.%.

A kind of single cell of thermo battery comprising positive electrode, electrolyte and negative electrode material, positive electrode include that rich lithium is molten Salt and positive electrode active materials；Electrolyte includes poor lithium fused salt and fused salt flow inhibitor or standard fused salt and fused salt flowing suppression Preparation；Negative electrode material includes poor lithium fused salt and negative electrode active material or standard fused salt and negative electrode active material；

Wherein, standard fused salt is the fused salt that molten salt composition corresponds to lowest total of the melting point, and rich lithium fused salt is lithium ion content height The fused salt of lithium ion content in standard fused salt, poor lithium fused salt be lithium ion content lower than in standard fused salt lithium ion content it is molten Salt.

Further, in preferred embodiments of the present invention, lithium in lithium ion content relative standard's fused salt in rich lithium fused salt High 5~the 25wt.% of ion concentration, in poor lithium fused salt in lithium ion content relative standard's fused salt lithium ion content it is low 10~ 40wt.%；

The content of positive electrode active materials is 70~90wt.% of positive electrode, and the content of flow inhibitor is electrolyte 30~60wt.%, the content of negative electrode active material are 70~95wt.% of negative electrode material.

The invention has the following advantages:

The present invention is by improving Li in anode in single cell of thermo battery design and preparation process⁺Salinity, same to phase Li in cathode or electrolyte should be reduced⁺The concentration of fused salt delays Li in discharge process anode⁺Concentration is remarkably decreased and causes electrification Learn electrolyte coagulation caused by the increase and molten salt composition segregation of polarization impedance.Meanwhile by further adjusting rich lithium fused salt With lithium ion concrete content range in poor lithium fused salt, good conductive effect is obtained, avoids causing to inhibit inclined because content is too low The effect of analysis is unobvious or too high levels and fused salt is caused to solidify, and does not have conductive effect.The present invention can be realized thermal cell Discharge performance is obviously improved, and is had broad application prospects and realistic meaning.

Detailed description of the invention

Fig. 1 is the present invention not using the single cell of thermo battery of the method for the present invention processing and using at the embodiment of the present invention 1 The single cell of thermo battery discharge performance comparison schematic diagram of reason.

Specific embodiment

The principle and features of the present invention will be described below with reference to the accompanying drawings, and the given examples are served only to explain the present invention, and It is non-to be used to limit the scope of the invention.The person that is not specified actual conditions in embodiment, according to normal conditions or the item suggested of manufacturer Part carries out.Reagents or instruments used without specified manufacturer is the conventional products that can be obtained by commercially available purchase.