CN104752777A - High-proportion zinc borate battery electrolyte and preparation method - Google Patents

Abstract

The invention relates to high-proportion zinc borate battery electrolyte and a preparation method. The molar ratio of potassium ions or/and sodium ions in the zinc battery electrolyte to boric acid ions is 0.28-2, and the total content of an additive in the electrolyte is less than or equal to 40 g/L. According to KOH or/and NaOH 2-6.2 mol/L, H3BO3 3.1-7 mol/L, LiOH.H2O 0.1-0.5 mol/L, a base solution is formed by blending with water as a solvent, then phytic acid, benzene-m-disulfonic acid, isophthalic acid-sulfonic acid, micro-nano SiO2 or micro-nano TiO2 are added, and after stirring, standing and naturally cooling, a 400-mesh screen is used for filtering to obtain the high-proportion zinc borate battery electrolyte. The high-proportion zinc borate battery electrolyte and the preparation method provided by the invention substantially solve the problems of dendrite growth, zinc element transfer, polar plate deformation and the like of a zinc cathode in charging and discharging processes, the cycle performance is significantly improved, and reliable technical guarantee is provided for enabling zinc series alkaline batteries to become a new generation of power batteries.

Description

A kind of high mixture ratio borate zinc battery electrolyte and its preparation method

Technical field

The invention belongs to zinc battery technical field of electrolyte, be specifically related to a kind of borate zinc battery electrolyte and its preparation method of high mixture ratio.

Background technology

Metallic zinc aboundresources, cheap, non-toxic, and there is higher voltage platform, energy density is high.Particularly alkali zinc nickel battery, its theoretical specific energy high (345A.h./kg), theoretical voltage high (1.75V), output current is large, with low cost and free from environmental pollution, thus can become a kind of candidate's power supply of electric automobile.But the secondary cell of zinc electrode is the large battery of the box secondary of pole piece especially, current practical bottleneck is main on service life, and affect circulative principal element and have: the dendritic growth of zinc electrode, Zn-ef ficiency displacement, pole plate distortion, from phenomenons such as corrosion and passivation, thus cause active material utilization to reduce, the capacity of battery declines, and electrode lost efficacy gradually.As in zinc-nickel cell, because zinc ion enters electrolyte, zinc in zinc electrode also can be caused to show poisoning effect to nickel electrode.Therefore, for addressing these problems, people do a lot of work.

In zinc electrode, activated zinc oxide adopts composite material, and metal zinc adopts alloying; As added calcium hydroxide, and various metals powder or oxide are (as PbO, Bi ₂o ₃, CdO, In ₂o ₃, Ga ₂o ₃, TI ₂o ₃deng) composition negative pole.In common alkaline electrolyte, obvious inhibitory action can be had to the distortion of zinc electrode and dendrite, but all fundamentally not solve the problem, the demand of practical application cannot be met.In electrolyte, because zinc electrode is much more serious than extent of corrosion in a neutral state under alkaline state, therefore, prior art is normally by adding various organic or inorganic additive in the electrolytic solution, to play the effect of following several respects: (1) reduces zinc oxide solubility in the electrolytic solution; (2) optimize the Structure and form of zinc sedimentary deposit, improve the electric current distribution uniformity of zinc electrode; (3) play corrosion inhibiter, suppress corrosion; (4) hinder or delay the generation of fine and close passivating film, prevent the generation of passivation.

Patents information is as follows: 1, application number 200710092303.0, denomination of invention " electrolyte composition for nickel-zinc cell ", the electrode and the electrolyte that disclose Ni-MH secondary battery have the composition that the formation of constrained tree dendrite is redistributed with the material of other form in zinc electrode, namely realize its goal of the invention by adding a small amount of phosphate, borate, indium compound, fluoride etc. and polyethylene glycol, TBAH, alkylphosphonate etc. in the alkaline electrolyte.In this electrolyte, additive component is complicated, and is only applicable to Horizontal electrode compact battery.2, application number 201210315842.7 discloses a kind of preparation method of alkaline zinc cell electrolyte, and its base soln comprises following composition: KOH, LiOH, NaOH, ZnO, Na ₂zn (OH) ₄, deionized water etc., its additive comprises following composition: polyacrylate, polyethylene glycol, polyacrylamide, zinc carbonate, Boratex, tungstate lithium, the additive of the said components accounting for base soln quality 1-3% is joined in base soln, heating is also fully stirred, and obtains alkaline battery electrolyte.Owing to have employed the KOH(40% of high concentration in the base soln of the method) and saturated zinc ion, therefore only better to the effect of a zinc battery.Meanwhile, also someone utilizes in electroplating system the principle of adding brightener, makes in charging process, zinc deposit bright, evenly, realizes controlling the ability of dendritic growth, but result unsatisfactory.Also have by between the positive/negative plate of zinc and air cell and some MH secondary battery, lay a slice nickel screen, electrically isolate from both positive and negative polarity, when the dendrite that zinc electrode grows touches nickel screen, produce galvanic interaction, dendrite is dissolved, to extend the charge and discharge circulation life of battery.

Generally speaking, MH secondary battery practical is at present Horizontal electrode compact battery mainly, mainly by reducing appropriate electrolyte, reaching the growth of further dendrite inhibition, service time is increased.But, in the box large-sized battery of MH secondary battery pole plate, still there is technical bottleneck.

Summary of the invention

The present invention aims to provide high mixture ratio borate electrolyte and the preparation method of a kind of electrode of being formed with zinc or zinc compound or battery.The common-ion effect that this electrolyte utilizes potassium borate (sodium) salt and potassium hydroxide (sodium) to produce, simultaneously under the cooperation of additive, overcomes zinc electrode in alkaline battery in use, easy constrained dendritic growth, distortion, Zn-ef ficiency such as to move at the bad phenomenon, and its cycle performance is significantly improved.

For achieving the above object, the technical solution used in the present invention is as follows:

A kind of high mixture ratio borate zinc battery electrolyte, it is characterized in that: be made up of base soln and additive, wherein, potassium ion, or/and sodium ion, is 0.28 ~ 2 with the ratio of the molal quantity of borate ion, additive total content≤40g/L in the electrolytic solution.

In described base soln, the molality of each component is:

KOH is or/and NaOH 2 ~ 6.2 mol/L

H ₃BO ₃3.1～7 mol/L

LiOH.H ₂O 0.1～0.5 mol/L

Solvent is pure water.

Described additive is made up of organic additive and/or inorganic additive, and described organic additive is the combination of any one or a few material following: six phosphate ester of cyclohexanhexanol, a benzenedisulfonic acid, M-phthalic acid monosulfonic acid; Described inorganic additive is micro-nano SiO ₂or micro-nano TiO ₂.

The preparation method of described high mixture ratio borate zinc battery electrolyte is:

1) preparation of base soln

By molality, each component after weighing is slowly joined and is equipped with in the alkaline-resisting reactor of pure water, stir, after utilizing reaction heat to dissolve, namely obtain base soln;

2) preparation of electrolyte

In the base soln prepared, add additive stir 30 minutes, leave standstill, naturally after cooling, filter with 400 eye mesh screens, demarcate concentration with pure water.

Operation principle of the present invention and Advantageous Effects are:

1, the present invention is the very weak acid utilizing borate, by forming common-ion effect with potassium hydroxide or NaOH and realize.In the electrolytic solution, zinc ion concentration can lower than ten thousand/, when discharge and recharge, utilize free hydroxyl, simultaneously under the mating reaction of additive of the present invention, effectively can release more than 1/3rd of zinc total amount theoretical capacity, thus reach battery practical application request.Because in electrolyte, zincic acid ion concentration is extremely low, thus cut off the route of metastasis of zincic acid radical ion, make electrolytic solution reach minimum to metal ion cyclic deposition speed in the corrosion of battery lead plate and electrolyte, and then effectively control the transfer of Zn-ef ficiency, dendritic growth, pole plate is out of shape.

2, when electrolyte application of the present invention, zinc electrode state is similar to cadmium electrode, in zinc electrode, active material is mainly exchanged for master with direct electron when discharge and recharge, generally, in electrolyte, the borate of high mixture ratio can cause electrolyte ion conductivity to decline, thus cause battery charging and discharging amount to decline, even cannot charge and discharge.Although the molar concentration of electrolyte mesoboric acid of the present invention is up to 3.1 ~ 7 mol/L, the i.e. molal quantity of potassium ion or sodium ion, or the total mole number of potassium, sodium ion, be 0.28 ~ 2 with the ratio of the molal quantity of borate ion, but after adding organic active agent, zincode plate surface of active material deposit is rendered as loose type, and because passivation phenomenon disappears, battery charging and discharging circulation is good.

3, the present invention is by the multiple organic additive of coupling and inorganic additive, serve good synergy, both respective advantage had been given full play to, respective shortcoming can be suppressed again, organic additive can improve the wettability of polar board surface, and significantly reduce the exchange resistance of electrolyte, inorganic particles is in electrolyte movement, wash away the crystallite dendrite of zinc electrode surface nascent state, thus effectively inhibit the phenomenons such as the dendritic growth of zinc electrode, distortion, corrosion and passivation.

4, the present invention breaches the technical bottleneck of zinc alkaline secondary cell, substance solves the dendritic growth of zinc load in charge and discharge process, Zn-ef ficiency shifts, and the problems such as pole plate deformation, become electrokinetic cell of new generation for making zinc system alkaline battery and provide reliable technical guarantee.

5, the key features of electrolyte of the present invention is, MH secondary battery zinc load (comprising large box type pad electrode) still can control zinc electrode dendritic growth when not adding other corrosion inhibiter, and Zn-ef ficiency shifts, and pole plate is out of shape, and work times surpasses 500 times.

Embodiment

embodiment 1

Base soln

KOH 336g

H ₃BO ₃ 244g

LiOH.H ₂O 5g

Additive

Six phosphate ester of cyclohexanhexanol 10g

Between benzenedisulfonic acid 10g

M-phthalic acid monosulfonic acid 10g

Micro-nano SiO ₂5g

Get alkaline-resisting 2L reactor, install 600mL pure water additional, slowly join by each component after above weight weighing in reactor, stirring and dissolving obtains base soln; In base soln, slowly add the additive of above-mentioned weight proportion, stir 10 minutes, demarcate 1L amount of solution with pure water, continue stirring 30 minutes, leave standstill cooling, filter with 400 order nickel screens.

embodiment 2

Base soln

KOH 360g

H ₃BO ₃ 320g

LiOH.H ₂O 12g

Additive

Six phosphate ester of cyclohexanhexanol 12g

Between benzenedisulfonic acid 8g

M-phthalic acid monosulfonic acid 10g

Micro-nano TiO ₂10g

Get alkaline-resisting 3L reactor, install 0.9L pure water additional, by KOH, LiOH.H after weighing ₂o slowly joins in reactor, stirs, to be dissolved complete after, more slowly add the boric acid of weighing, stir 15 minutes; Then the additive of each weighing is slowly joined in above-mentioned reactor, stir 10 minutes, with pure water volumetric solution to 1.5L, continue stirring 30 minutes, leave standstill cooling, filter with 400 order nickel screens.

embodiment 3

Base soln

KOH 110g

H ₃BO ₃ 189g

LiOH.H ₂O 13g

Additive

Six phosphate ester of cyclohexanhexanol 5g

Between benzenedisulfonic acid 5g

Micro-nano TiO ₂3g

Get alkaline-resisting 2L reactor, install 600mL pure water additional, slowly join by each component after above weight weighing in reactor, stirring and dissolving obtains base soln; In base soln, slowly add the additive of above-mentioned weight proportion, stir 10 minutes, demarcate 1L amount of solution with pure water, continue stirring 30 minutes, leave standstill cooling, filter with 400 order nickel screens.

embodiment 4

Base soln

KOH 196g

H ₃BO ₃ 190g

LiOH.H ₂O 4.2g

Additive

Six phosphate ester of cyclohexanhexanol 15g

M-phthalic acid monosulfonic acid 10g

Micro-nano SiO ₂10g

Get alkaline-resisting 2L reactor, install 600mL pure water additional, slowly join by each component after above weight weighing in reactor, stirring and dissolving obtains base soln; In base soln, slowly add the additive of above-mentioned weight proportion, stir 10 minutes, demarcate 1L amount of solution with pure water, continue stirring 30 minutes, leave standstill cooling, filter with 400 order nickel screens.

embodiment 5

Base soln

KOH 350g

H ₃BO ₃ 430g

LiOH.H ₂O 8.4g

Additive

Six phosphate ester of cyclohexanhexanol 20g

Micro-nano SiO ₂5g

Get alkaline-resisting 2L reactor, install 600mL pure water additional, slowly join by each component after above weight weighing in reactor, stirring and dissolving obtains base soln; In base soln, slowly add the additive of above-mentioned weight proportion, stir 10 minutes, demarcate 1L amount of solution with pure water, continue stirring 30 minutes, leave standstill cooling, filter with 400 order nickel screens.

embodiment 6

Base soln

NaOH 80g

H ₃BO ₃ 190g

LiOH.H ₂O 21g

Additive

Between benzenedisulfonic acid 5g

M-phthalic acid monosulfonic acid 15g

Micro-nano TiO ₂8g

Get alkaline-resisting 2L reactor, install 600mL pure water additional, slowly join by each component after above weight weighing in reactor, stirring and dissolving obtains base soln; In base soln, slowly add the additive of above-mentioned weight proportion, stir 10 minutes, demarcate 1L amount of solution with pure water, continue stirring 30 minutes, leave standstill cooling, filter with 400 order nickel screens.

embodiment 7

Base soln

NaOH 180g

H ₃BO ₃ 366g

LiOH.H ₂O 170g

Additive

Six phosphate ester of cyclohexanhexanol 5g

Between benzenedisulfonic acid 5g

M-phthalic acid monosulfonic acid 15g

Get alkaline-resisting 2L reactor, install 600mL pure water additional, slowly join by each component after above weight weighing in reactor, stirring and dissolving obtains base soln; In base soln, slowly add the additive of above-mentioned weight proportion, stir 10 minutes, demarcate 1L amount of solution with pure water, continue stirring 30 minutes, leave standstill cooling, filter with 400 order nickel screens.

embodiment 8

Base soln

KOH 140g

NaOH 120g

H ₃BO ₃ 244g

LiOH.H ₂O 15g

Additive

Six phosphate ester of cyclohexanhexanol 10g

M-phthalic acid monosulfonic acid 15g

Get alkaline-resisting 2L reactor, install 600mL pure water additional, slowly join by each component after above weight weighing in reactor, stirring and dissolving obtains base soln; In base soln, slowly add the additive of above-mentioned weight proportion, stir 10 minutes, demarcate 1L amount of solution with pure water, continue stirring 30 minutes, leave standstill cooling, filter with 400 order nickel screens.

embodiment 9

Base soln

KOH 200g

H ₃BO ₃ 280g

LiOH.H ₂O 11g

Additive

Micro-nano SiO2 10g

Get alkaline-resisting 2L reactor, install 600mL pure water additional, slowly join by each component after above weight weighing in reactor, stirring and dissolving obtains base soln; In base soln, slowly add the additive of above-mentioned weight proportion, stir 10 minutes, demarcate 1L amount of solution with pure water, continue stirring 30 minutes, leave standstill cooling, filter with 400 order nickel screens.

embodiment 10

NaOH 128g

H ₃BO ₃ 305g

LiOH.H ₂O 15g

Get alkaline-resisting 2L reactor, install 600mL pure water additional, slowly join by each component after above weight weighing in reactor, stirring and dissolving also demarcates 1L amount of solution with pure water, continues stirring 30 minutes, leaves standstill cooling, filters with 400 order nickel screens.

Claims (4)

1. a high mixture ratio borate zinc battery electrolyte, is characterized in that: be made up of base soln and additive, and wherein, potassium ion, or/and sodium ion, is 0.28 ~ 2 with the ratio of the molal quantity of borate ion, additive total content≤40g/L in the electrolytic solution.

2. high mixture ratio borate zinc battery electrolyte according to claim 1, is characterized in that: in described base soln, the molality of each component is:

KOH is or/and NaOH 2 ~ 6.2 mol/L

H ₃BO ₃3.1～7 mol/L

LiOH.H ₂O 0.1～0.5 mol/L

Solvent is pure water.

3. high mixture ratio borate zinc battery electrolyte according to claim 1, it is characterized in that: described additive is made up of organic additive and/or inorganic additive, described organic additive is the combination of any one or a few material following: six phosphate ester of cyclohexanhexanol, a benzenedisulfonic acid, M-phthalic acid monosulfonic acid; Described inorganic additive is micro-nano SiO ₂or micro-nano TiO ₂.

4. the preparation method of high mixture ratio borate zinc battery electrolyte according to claim 1, is characterized in that processing step is as follows:

1) preparation of base soln

By molality, each component after weighing is slowly joined and is equipped with in the alkaline-resisting reactor of pure water, stir, after utilizing reaction heat to dissolve, namely obtain base soln;

2) preparation of electrolyte

In the base soln prepared, add additive stir 30 minutes, leave standstill, naturally after cooling, filter with 400 eye mesh screens, demarcate concentration with pure water.