CN112599828B - A Novel Titanium Manganese Single Flow Battery - Google Patents

Abstract

The invention discloses a single-flow battery, which comprises a titanium-manganese battery module, a circulating pump, a negative electrode electrolyte liquid storage tank, a negative electrode electrolyte, a negative electrode electrolyte input pipeline and a negative electrode electrolyte output pipeline; the The titanium-manganese battery module includes a positive electrode, a separator, and a negative electrode; the redox pair of the negative electrode is Ti ³⁺ /Ti ⁴⁺ , and the redox pair of the positive electrode is Mn ²⁺ /MnO ₂ , which solves the problem of the precipitation of MnO ₂ in the positive electrode. It is easy to block the positive electrode, and greatly reduces the cost of the battery, which is conducive to the popularization and application of flow batteries, and has the characteristics of long cycle life, simple structure and simple manufacturing process.

Description

A Novel Titanium Manganese Single Flow Battery

technical field

The invention belongs to the field of batteries, and in particular relates to a novel titanium-manganese single-flow battery.

Background technique

With the development of the economy, the demand for energy is increasing day by day, and the environmental problems caused by the massive consumption of fossil energy are becoming more and more prominent. The large-scale utilization of renewable energy and the realization of energy diversification have become important strategies for energy security and sustainable development in all countries in the world. However, the discontinuity and instability of renewable energy such as wind energy and solar energy make their direct utilization difficult. Therefore, the use of energy storage technology to achieve continuous supply of renewable energy has become the key to solving the above problems. Flow battery has become one of the most promising technologies in the large-scale energy storage market due to its flexible design (separate design of energy and power), good safety and long life.

At present, the relatively mature flow systems include all-vanadium flow batteries, zinc-bromine flow batteries, and sodium bromine polysulfide systems. However, the all-vanadium redox flow battery faces the problems of high cost and strong acidity and corrosiveness of the electrolyte; in addition, the zinc-bromine redox flow battery system and the sodium-bromine polysulfide system are faced with the problems of the volatility and corrosion of bromine, causing environmental pollution. serious. Therefore, the development of low-cost, environment-friendly, and high-reliability new flow batteries becomes particularly important.

As a new type of low-cost, environmentally friendly flow battery, titanium-manganese flow battery has gradually attracted the attention of researchers. However, the disproportionation reaction of positive trivalent manganese ions generates MnO ₂ deposits, which is easy to cause positive blockage and stack damage. , the formation of MnO ₂ deposits is generally avoided by controlling the concentration of manganese ions, but it is difficult to completely avoid the occurrence of failures, and only the single electron transfer reaction from manganese ions to manganese ions can be used, which seriously hinders titanium Development of manganese flow batteries.

SUMMARY OF THE INVENTION

In view of the above problems, the application proposes a new type of titanium-manganese single-flow battery, the positive electrode electrolyte does not flow, and the disproportionation reaction of trivalent manganese ions is fully utilized to generate MnO ₂ deposits, and the reaction of divalent manganese ions to trivalent manganese ions is made. The process is broadened to the reaction process from divalent manganese ions to tetravalent manganese ions, which not only improves the energy density of the cathode electrolyte, but also solves the potential risk of cathode clogging in titanium-manganese flow batteries, which is beneficial to the development of titanium-manganese flow batteries. Promote the application.

For achieving the above object, the concrete technical scheme of the present invention is as follows:

The invention provides a single-flow battery, which comprises a titanium-manganese battery module, a circulating pump, a negative electrolyte storage tank, a negative electrolyte, a negative electrolyte input pipeline and a negative electrolyte output pipeline ;

The titanium-manganese battery module includes a single cell or a stack formed by connecting two or more single cells in series;

The single cell includes positive and negative terminal plates, a current collector, a positive bipolar plate sequentially stacked between the positive and negative terminal plates and the current collector, a positive electrode material placed in the cavity of the positive electrode frame, and a battery. A separator, a negative electrode material placed in the cavity of the negative electrode frame, and a negative electrode bipolar plate;

The stack includes positive and negative terminal plates, a current collector plate, and N sequentially stacked positive bipolar plates between the positive and negative terminal plates and the current collector plates, and a positive electrode placed in the cavity of the positive electrode frame. A combination of materials, battery separators, negative electrode materials placed in the cavity of the negative electrode frame, and negative electrode bipolar plates; the N combinations are connected in series; N≥2, N is an integer;

The negative electrolyte storage tank is communicated with the negative electrode through the negative electrolyte input pipeline and the negative electrolyte output pipeline, and the circulating pump is arranged on the negative electrolyte input pipeline;

The single-flow battery also includes a positive electrode electrolyte, which is the same as the negative electrode electrolyte; a cavity is provided between the positive electrode and the diaphragm; the positive electrode electrolyte does not flow and is sealed in the in the cavity;

The redox couple of the negative electrode is Ti ³⁺ /Ti ⁴⁺ , and the redox couple of the positive electrode is Mn ²⁺ /MnO ₂ .

Negative electrode: 2Ti ³⁺ +2H ₂ O-2e-=2TiO ²⁺ +4H ⁺ ; Positive electrode: MnO ₂ +4H ⁺ +2e-=Mn ²⁺ +2H ₂ O

Based on the above technical solution, preferably, the positive electrode material in the positive electrode frame cavity between the positive electrode bipolar plate and the battery separator is a porous material, the positive electrode electrolyte is sealed in the pores of the porous material, and the positive electrode The MnO ₂ particulate matter is deposited on the surface of the porous material, the specific surface area of the porous material is greater than 0.2-1000 m ² /g, and the porosity is 1-60%.

Based on the above technical solutions, preferably, the positive electrode side adopts a sealed structure, and there is no need to separately configure a positive electrode electrolyte storage tank, a circulating pump and a circulating pipeline, and the positive electrode is provided with a positive electrode electrolyte solution inlet and outlet, which is used for positive electrode electrolysis before battery operation. liquid filling.

Based on the above technical solution, preferably, the negative electrode electrolyte is a sulfuric acid solution containing manganese ions (Mn ²⁺ ) and titanium ions (including Ti ³⁺ and Ti ⁴⁺ ), and the ratio of the two ions is not limited. The total concentration of ions is in the range of 1 mol·dm ^-3 to 5 mol·dm ^-3 , and the total concentration of manganese ions is in the range of 0 to 5 mol·dm ^-3 .

Based on the above technical solution, preferably, the positive electrode electrolyte is a sulfuric acid solution containing manganese ions (including Mn ²⁺ , Mn ³⁺ ) and titanium ions (Ti ⁴⁺ ), and the total concentration of manganese ions is 1 mol·dm ^-3 ～ 5 mol·dm ^-3 , the MnO ₂ particles formed by the reaction of the positive electrode are deposited on the surface of the porous material, and the deposition amount is 0.1 g/cm ² -100 g/cm ² ; the total concentration of titanium ions is 0 - 5 mol · dm ^-3 .

Based on the above technical solutions, preferably, both the positive electrode and the negative electrode are made of plate-like or porous metal or carbon materials; the positive electrode is used as a substrate to coat a positive electrode active material; the positive electrode active material is MnO ₂ particulate material.

Based on the above technical solutions, preferably, the carbon material is carbon felt, carbon cloth or carbon paper.

Based on the above technical solution, preferably, the coating amount of the positive electrode active material on the positive electrode is 0.1 g/cm ² to 100 g/cm ² .

Based on the above technical solutions, preferably, the titanium-manganese battery module further includes a negative electrode frame and a positive electrode frame; the positive electrode is located in the positive electrode frame, and the negative electrode is located in the negative electrode frame; the thickness of the negative electrode frame is The thickness of the negative electrode is 0.1-4 mm, the thickness of the negative electrode is 0.05-5 mm; the thickness of the positive electrode frame is 1-20 mm, and the thickness of the positive electrode is 1-30 mm.

Based on the above technical solutions, preferably, the membrane is an ion exchange membrane, a porous membrane or a microporous membrane.

beneficial effect

1. This application proposes a novel titanium-manganese single-flow battery. Both the positive and negative electrolytes contain manganese ions and titanium ions, which avoids cross-contamination of the positive and negative electrolytes.

2. This application solves the problem that the positive electrode MnO ₂ is easily blocked during the flow process by sealing the positive electrode electrolyte, and greatly reduces the cost of the battery, which is conducive to the popularization and application of flow batteries, and has the advantages of Long cycle life, simple structure and simple manufacturing process.

3. The positive electrode electrolyte of the present application contains manganese ions. During the positive electrode reaction process, the presence of titanium ions can delay the progress of the disproportionation reaction from Mn ³⁺ to MnO ₂ , so that the generated MnO ₂ can be dispersed in the electrolyte to avoid instantaneous generation A large amount of _MnO2 agglomerates to cause clogging of electrode pores and improve battery life.

4. The present application utilizes the reaction process from positive divalent manganese ions to tetravalent manganese ions, which greatly improves the energy density of the positive electrode electrolyte compared with the previous reaction process from divalent manganese ions to trivalent manganese ions.

Description of drawings

1 is a schematic diagram of a single cell of the titanium-manganese single-flow battery of Example 1;

Fig. 2 is the cycle efficiency curve of titanium-manganese single-flow battery in Example 1;

In the figure: 1. Positive end plate; 2. Negative end plate; 3. Positive electrode; 4. Negative electrode; 5. Diaphragm; 6. Circulating pump; 7. Negative electrolyte storage tank.

Detailed ways

The raw materials used in the examples are conventional products that can be obtained from the market.

Example 1

1. Electrolyte configuration:

The positive and negative electrolytes are the same, each with 40 ml, and the electrolyte contains 1 mol·dm ^-3 manganese sulfate and 1 mol·dm ^-3 titanyl sulfate.

2. Battery assembly:

The single cells are assembled in the order of positive electrode plate, positive electrode (3×3cm ² graphite felt), separator (Nafion211), negative electrode (3×3cm ² graphite felt), and negative electrode end plate;

Assemble the single cell with the circulating pump, the negative electrolyte storage tank, the negative electrolyte input pipeline and the negative electrolyte output pipeline; make the negative electrolyte storage tank pass through the negative electrolyte input pipeline and the negative electrolyte output pipeline The circuit is connected to the negative electrode, the circulating pump is arranged on the negative electrode electrolyte input pipeline, and the positive electrode electrolyte is sealed in the cavity between the positive electrode and the diaphragm; the assembled single cell structure and system are shown in Figure 1.

3. Battery test:

When the negative electrolyte flow rate is 5ml/min, the charge-discharge current density is 80-100mA/cm ² , as shown in Figure 2, the average energy efficiency of the battery is about 80%, and the cycle life is over 2000.

Comparative Example 1

The difference with Example 1 is: the positive electrolyte circulates, specifically: the positive electrolyte is communicated with the positive electrode through the positive electrolyte storage tank input pipeline and the positive electrolyte output pipeline, and the circulating pump is set at the positive electrolyte input. on the pipeline.

Table 1 Comparative Example 1 Titanium-manganese dual flow battery and Example 1 Titanium-manganese single flow battery performance comparison

Running electrical density (mA·cm^-2) average energy efficiency Cycle life (cycles) Energy density (Wh·L^-1) Cost (yuan/kWh) Titanium manganese single flow battery 100 82% ＞2000 35 1500 Titanium manganese dual flow battery 100 75% ≈200 20 2600

Table 1 compares the single-cell performance of the titanium-manganese single-flow battery and the dual-flow battery. The comparison shows that when the current density of the titanium-manganese single-flow battery is 100 mA·cm ^-2 , the energy efficiency is above 80%, which is higher than Titanium manganese dual flow battery. The cycle life of the battery as well as the cost per kilowatt hour, the single flow battery has obvious beneficial effects. Most importantly, the titanium-manganese single-flow battery can broaden the reaction process from divalent manganese ions to trivalent manganese ions to the reaction process of divalent manganese ions to tetravalent manganese ions, so the energy density is close to that of titanium-manganese dual-flow. Twice the battery.

Claims (9)

1. a single flow battery, it is characterized in that: described single flow battery comprises titanium manganese battery module, circulating pump, negative electrolyte liquid storage tank, negative electrolyte, negative electrolyte input pipeline and negative electrolyte output pipeline; The titanium-manganese battery module includes a single cell or a stack formed by connecting two or more single cells in series; The single cell includes positive and negative terminal plates and a positive electrode, a separator and a negative electrode sequentially stacked between the positive and negative terminal plates; The stack includes positive and negative end plates and N combinations of positive electrodes, separators and negative electrodes stacked in sequence between the positive and negative end plates; the N combinations are connected in series; N≥2, N takes integer; The negative electrolyte storage tank is communicated with the negative electrode through the negative electrolyte input pipeline and the negative electrolyte output pipeline, and the circulating pump is arranged on the negative electrolyte input pipeline; The single-flow battery further includes a positive electrode electrolyte, and a cavity is provided between the positive electrode and the diaphragm; the positive electrode electrolyte does not flow and is sealed in the cavity; The redox couple of the negative electrode is Ti ³⁺ /Ti ⁴⁺ , and the redox couple of the positive electrode is Mn ²⁺ /MnO ₂ ; Both the positive electrode and the negative electrode are made of porous metal or carbon material; the positive electrode is used as a matrix to coat a positive electrode active material; the positive electrode active material is MnO ₂ particles. 2 . The single-flow battery according to claim 1 , wherein the positive electrode frame cavity between the bipolar plate of the positive electrode and the battery separator is provided with a positive electrode material, and the positive electrode material is a porous material, 2 . The positive electrode electrolyte is sealed in the pores of the porous material, and the MnO ₂ particulate matter generated by the positive electrode reaction is deposited on the surface of the porous material; the deposition amount is 0.1 g/cm ² to 100 g/cm ² ; the porous The specific surface area of the material is greater than 0.2-1000 m ² /g, and the porosity is 1-60%. 3. The single-flow battery according to claim 1, wherein the positive electrolyte is a sulfuric acid solution containing divalent, trivalent manganese ions and tetravalent titanium ions, and the total concentration of the manganese ions is 1 mol· dm ^-3 to 5 mol·dm ^-3 , and the total concentration of the titanium ions is 0 to 5 mol·dm ^-3 . 4 . The single flow battery according to claim 1 , wherein the negative electrode electrolyte is a sulfuric acid solution containing trivalent, tetravalent titanium ions and divalent manganese ions, and the total concentration of the titanium ions is 1- 5 mol·dm ^-3 , and the total concentration of the manganese ions is 0-5 mol·dm ^-3 . 5 . The single-flow battery according to claim 1 , wherein the positive electrode is provided with a positive electrode electrolyte inlet and an outlet, which are used for filling the positive electrode electrolyte before battery operation. 6 . 6 . The single flow battery according to claim 1 , wherein the carbon material is carbon felt, carbon cloth or carbon paper. 7 . 7 . The single-flow battery according to claim 1 , wherein the coating amount of the positive electrode active material on the positive electrode is 0.1 g/cm ² to 100 g/cm ² . 8 . The single-flow battery according to claim 1 , wherein the titanium-manganese battery module further comprises a negative electrode frame and a positive electrode frame; the positive electrode is located in the positive electrode frame, and the negative electrode is located in the negative electrode. 9 . Inside the electrode frame; the thickness of the negative electrode frame is 0.1-4 mm, the thickness of the negative electrode is 0.05-5 mm; the thickness of the positive electrode frame is 1-20 mm, and the thickness of the positive electrode is 1-30 mm. 9 . The single-flow battery according to claim 1 , wherein the separator is an ion exchange membrane or a porous membrane. 10 .

Images