KR20240057595A - A cathode active material precursor for a lithium secondary battery, and a method for manufacturing the same - Google Patents

Abstract

The present invention is manufactured under conditions in which the energy index (EI), defined as the product of the synthesis temperature (℃) and the stirring speed energy (Wh/kg), is in the range of 7,200 ℃·Wh/kg ≤ EI ≤ 15,600 ℃·Wh/kg This relates to a positive electrode active material precursor for a secondary battery represented by the following formula (1), which is characterized in that, in the case of a precursor manufactured in a range that satisfies a specific energy index value according to the present invention, the stacking fault value is reduced and the positive electrode The crystallinity of the active material is excellent, and secondary batteries using it have excellent lifespan characteristics at high temperatures.
Formula 1
Ni _(1-xyz) Co _x Mn _y A _z (OH) ₂
In the above formula, A includes one or more elements selected from the group consisting of Al, B, Ba, Ce, Cr, F, Li, Mo, P, Sr, Ti, and Zr, and x, y, and z are each 0.2≥x ≥0, 0.1≥y≥0, 0.05≥z≥0 are satisfied.

Description

Cathode active material precursor for lithium secondary battery, and method for manufacturing same {A CATHODE ACTIVE MATERIAL PRECURSOR FOR A LITHIUM SECONDARY BATTERY, AND A METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a cathode active material precursor for lithium secondary batteries, and a method for manufacturing the same. Specifically, a cathode active material precursor for lithium secondary batteries with high crystallinity and excellent high-temperature lifespan characteristics by being manufactured under conditions that satisfy an energy index value in a specific range; and methods for producing the same.

The components of a lithium-ion secondary battery are a positive electrode material, a negative electrode material, an electrolyte, and a separator, and the key material among these is the positive electrode material. In order to manufacture such a cathode material, the synthesis of the precursor must first be carried out, and a common synthesis method is a coprecipitation method using an aqueous metal solution, a complexing agent, and a precipitant. The synthesis process using coprecipitation, which has been most widely used commercially so far, can be divided into the CSTR process and the batch process, and the precursor is synthesized by simultaneously adding an aqueous metal solution, complexing agent, and precipitant.

In general, when synthesizing a precursor, the synthesis temperature is set, the concentration and flow rate of the complexing agent and precipitant are adjusted according to the shape and characteristics of the desired precursor, and the entire phase is uniformly mixed through a stirrer to proceed with the synthesis.

At this time, the synthesis temperature and stirring speed directly affect the growth pattern and crystal structure of the precursor particles. Unless there are special cases, the synthesis temperature of the precursor is performed below 60℃. Synthesis temperature affects the creation of initial particles, the growth rate of particles, and the formation of the crystal structure of the precursor. If synthesis is carried out at an excessively low temperature, the entire reaction phase becomes too stabilized and the particle growth rate slows down. If other measures are taken to increase the growth rate, the possibility of fine particles occurring increases. Conversely, if synthesized at an excessively high temperature, the growth rate of the particles increases, but the possibility of the particle size distribution becoming too wide increases. Therefore, it is very important to proceed with the reaction at an appropriate temperature depending on the precursor.

Korean Patent No. 10-2066461 is a method of producing a composite metal hydroxide precursor as a cathode active material for a lithium secondary battery containing nickel, cobalt, and manganese through a coprecipitation reaction. In the step of inducing the coprecipitation reaction, compared to the total number of moles of metal ions in the metal salt aqueous solution, The number of moles of ammonia is adjusted to 1: 0.95 to 1: 1.5 [total number of moles of metal ions in aqueous metal salt solution: number of moles of ammonia], so that when EBSD analysis is performed at a azimuth difference (△g) of 30 degrees or less, the number of moles is [001] based on the ND axis. The orientation in the direction is 22% or more, and the orientation in the [120] + [210] direction based on the RD axis is 87% or less when EBSD analysis is performed at an azimuth difference (△g) of 30 degrees or less, and the azimuth difference (△g) is 87% or less. ) A method for manufacturing an anode precursor with an orientation of 52% or less in the [120] direction relative to the RD axis is proposed when performing EBSD analysis at temperatures below 30 degrees.

In addition, in Korean Patent No. 10-2082516, when manufacturing a cathode active material for a sodium secondary battery, an aqueous metal salt solution includes M1, M2, and M3, the concentration of M1 is the same, and the concentration of M2 and the concentration of M3 are different from each other in the center. A first step of preparing an aqueous metal salt solution for forming a metal salt solution and an aqueous metal salt solution for forming a surface portion; Mixing the aqueous metal salt solution for forming the core and the aqueous metal salt solution for forming the surface portion so that the mixing ratio gradually changes from 100 v%: 0 v% to 0 v%: 100 v%, while simultaneously mixing the chelating agent and the basic aqueous solution in the reactor. A second step of forming a precipitate so that the concentration of M1 is constant from the center to the surface, and the concentrations of M2 and M3 have a continuous concentration gradient from the center to the surface; A third step of preparing an active material precursor by drying or heat treating the obtained precipitate; And a fourth step of mixing the active material precursor and sodium salt and then heat treating, wherein M1, M2, and M3 are selected from the group consisting of Ni, Co, Mn, and combinations thereof. A method of producing a cathode active material for a sodium secondary battery. presented.

The above patents propose technologies that limit synthesis temperature and stirring speed when manufacturing cathode active material precursors for secondary batteries.

However, expressing the kinetic energy applied in the reactor in terms of stirrer RPM when synthesizing a precursor for a lithium ion secondary battery cathode material is very limited in defining the exact kinetic energy applied to the reactor. This is because the stirring speed of the reactor that synthesizes the precursor is generally very dependent on the size of the reactor.

That is, as the volume of the reactor decreases, the size of the stirrer becomes smaller and the stirring RPM increases accordingly, and as the volume of the stirrer increases, the stirring RPM decreases. For example, the stirring speed of reactors of 10L or less used in laboratories ranges from hundreds to thousands of RPM, and the stirring speed of mass production reactors of 10 ㎥ or more used in industrial sites ranges from tens to no more than 200 RPM for synthesis. Proceed.

Therefore, defining the stirring energy applied to the precursor as stirring RPM has limitations in representing the actual energy applied to the reactor during the actual synthesis process. Additionally, during the precursor synthesis process, the stirring speed is generally sequentially decreased or increased depending on the synthesis time. Therefore, specifying the precursor's stirring speed can be said to be a very vague definition.

Korean registered patent 10-2066461 Korean registered patent 10-2082516

Accordingly, in the present invention, in the synthesis of precursors for conventional cathode active materials for lithium secondary batteries, in order to solve the problem of different physical properties of the precursors produced depending on the synthesis temperature and stirring speed, the kinetic energy applied to the reactor from the start of precursor synthesis to the end is transferred to the stirrer. By substituting the input electrical energy for definition and at the same time including the synthesis temperature, another energy source applied to the reactor, in the total energy, we attempted to provide conditions for manufacturing the precursor of the cathode active material for lithium secondary batteries in optimal conditions.

Accordingly, the purpose of the present invention is to provide a cathode active material precursor for lithium secondary batteries that is manufactured within a certain energy index range, has low stacking defects, has high crystallinity, and exhibits excellent high-temperature characteristics.

In addition, another object of the present invention is to provide a method for manufacturing a cathode active material precursor for a lithium secondary battery having the above characteristics.

Additionally, an object of the present invention is to provide a positive electrode active material for a lithium secondary battery obtained by sintering the prepared precursor.

The positive electrode active material precursor for a secondary battery according to an embodiment of the present invention has an energy index (EI) defined as the product of the synthesis temperature (°C) and the stirring rate energy (Wh/kg) of 7,200°C·Wh/kg≤EI It may be represented by the following formula 1, which is characterized in that it is manufactured under conditions in the range of ≤ 15,600°C·Wh/kg.

Formula 1

Ni _(1-xyz) Co _x Mn _y A _z (OH) ₂

In the above formula, A includes one or more elements selected from the group consisting of Al, B, Ba, Ce, Cr, F, Li, Mo, P, Sr, Ti, and Zr, and x, y, and z are each 0.2≥x ≥0, 0.1≥y≥0, 0.05≥z≥0 are satisfied.

According to one embodiment of the present invention, the particle size of the precursor is preferably 13.5 to 14.5 ㎛ based on D50, and the (D90-D10)/D50 value representing the particle size distribution is preferably 0.30 to 0.55.

Additionally, according to one embodiment of the present invention, the synthesis temperature may satisfy a value between 45°C (318K) and 60°C (343K).

In addition, the stirring speed energy is the kinetic energy applied to the synthesis system through stirring from the start of synthesis to the end, and the range is preferably 160 to 260 Wh as the total electric energy for the final obtained precursor production (kg).

The method for producing a positive electrode active material precursor for a secondary battery represented by the following formula (1) according to the present invention has an energy index (EI) value of 7,200 °C, which is defined as the product of the synthesis temperature (°C) and the stirring rate energy (Wh/kg). ·Wh/kg ≤ EI ≤ 15,600°C ·Wh/kg may be manufactured including the step of manufacturing under conditions in the range.

Formula 1

Ni _(1-xyz) Co _x Mn _y A _z (OH) ₂

In the above formula, A includes one or more elements selected from the group consisting of Al, B, Ba, Ce, Cr, F, Li, Mo, P, Sr, Ti, and Zr, and x, y, and z are each 0.2≥x ≥0, 0.1≥y≥0, 0.05≥z≥0 are satisfied.

Additionally, the present invention can provide a cathode active material for a lithium secondary battery obtained by sintering the precursor.

According to the present invention, by manufacturing a cathode active material precursor for a lithium secondary battery within a range that satisfies a specific energy index value, the stacking fault value is reduced, thereby improving the crystallinity of the cathode active material, and secondary batteries using the same are manufactured at high temperatures. It has excellent lifespan characteristics.

Figure 1 is a diagram illustrating the relationship between the XRD half width of the precursor and the corresponding XRD half width of the anode material according to the precursor synthesis temperature.
Figure 2 is a graph showing the FWHM values of the XRD (001) and (101) planes of Examples 1 and 2 and Comparative Example 1.
Figure 3 is a graph showing the FWHM values of the XRD (102) surface of Examples 1 and 2 and Comparative Example 1.
Figure 4 is a graph showing the life characteristics at high temperature of Examples 1 and 2 and Comparative Example 1.

The present invention will be described in more detail below.

The terms used herein are used to describe specific embodiments and are not intended to limit the invention.

As used herein, the singular forms include the plural forms unless the context clearly indicates otherwise. Additionally, when used herein, “comprise” and/or “comprising” means specifying the presence of stated features, numbers, steps, operations, members, elements and/or groups thereof. and does not exclude the presence or addition of one or more other shapes, numbers, operations, members, elements and/or groups.

The present invention relates to a cathode active material precursor for lithium secondary batteries that exhibits excellent physical properties by being manufactured within a certain energy index range, a method of manufacturing the same, and a cathode active material for lithium secondary batteries obtained by calcining the precursor.

The positive electrode active material precursor for the secondary battery according to the present invention is represented by the following formula (1), and the energy index (EI), which is defined as the product of the synthesis temperature (℃) and the stirring rate energy (Wh/kg), is 7,200 ℃. It is characterized by being manufactured under conditions in the range of Wh/kg ≤ EI ≤ 15,600°C·Wh/kg.

Formula 1

Ni _(1-xyz) Co _x Mn _y A _z (OH) ₂

In the above formula, A includes one or more elements selected from the group consisting of Al, B, Ba, Ce, Cr, F, Li, Mo, P, Sr, Ti, and Zr, and x, y, and z are each 0.2≥x ≥0, 0.1≥y≥0, 0.05≥z≥0 are satisfied.

In order to increase the uniformity of the precursor crystal structure, it is very effective to increase the total amount of energy each particle receives during synthesis within the range where differentiation does not occur. At this time, the total amount of energy is added to the synthesis system during precursor synthesis, and the representative energy that affects particle growth can be divided into heat energy and kinetic energy, with heat energy being added to the synthesis system in the form of synthesis temperature and kinetic energy being added to the synthesis system in the form of stirring.

In the present invention, as described above, the energy applied to the synthesis reactor during precursor synthesis is divided into heat energy and kinetic energy, and the energy index (EI) is defined as the product of these energies to produce precursors synthesized within a certain energy index range. I want to be specific.

Energy index (EI) = synthesis temperature (℃) x stirring speed energy (Wh/kg)

In general, synthesis temperature affects the crystal growth pattern of the precursor. The crystal formation conditions of the precursor primary particles, which are formed as the precursor particles grow, have a decisive influence on the characteristics of the anode after firing. According to the literature, it is reported that the anode characteristics are excellent when the primary particle crystal is dominated by the β phase, which has better arrangement characteristics between crystal constituent elements, than when the primary particle crystal is the α phase.

Next, referring to Figure 1, the XRD half width of the precursor and the corresponding XRD half width of the cathode material according to the precursor synthesis temperature are presented. As the synthesis temperature of the precursor increases, the half width of the (102) plane decreases. In general, a decrease in the half width of the (102) plane of the precursor means an increase in the β phase. Accordingly, the (003) plane of the anode material increases, which can be seen as a direct cause of improved high-temperature lifespan.

Therefore, it can be said that the synthesis temperature is very important in improving anode characteristics. Accordingly, the appropriate synthesis temperature proposed in the present invention is set in the range of 45 ℃ (318 K) to 60 ℃ (343 K), preferably 47 ℃ (320 K) to 52 ℃ (345 K), thereby increasing the β phase fraction inside the precursor particle. It can be increased, and as a result, the final cathode material has a crystalline phase that exhibits excellent high-temperature lifespan characteristics.

In addition, in the present invention, regardless of the size of the conventional reactor, it was simply limited to the stirring speed (rpm), and considering the fact that the meaning was ambiguous, it was defined as stirring speed energy rather than the concept of stirring speed, and stirred from the start of synthesis to the end. The concept of electrical energy used in the stirrer was applied to the kinetic energy applied to the synthetic system.

The electrical energy limited in the present invention means the total electrical energy (Wh) relative to the final precursor production (kg) obtained, and the total energy applied for actual stirring is 160 to 260 Wh/kg, more preferably 180 to 260 Wh/kg. It can be limited to 240 Wh/kg.

In general, in the precursor co-precipitation synthesis process, regardless of the CSTR process or the batch process, the metal aqueous solution and auxiliary materials injected into the reactor must be uniformly mixed within the reactor within the shortest possible time through stirring. At this time, the stirring speed is adjusted depending on the shape and particle size of the precursor to be synthesized.

In general, in batch processes, keeping the stirring speed too high causes the generation of fine powder, and when fine dust occurs, the particle growth rate slows down. On the other hand, if the stirring speed is kept too low, the speed at which the injected reactants are uniformly mixed inside the reactor may slow down, resulting in a broadened particle size distribution and excessively rapid growth of specific particles. Therefore, since maintaining an appropriate stirring speed during synthesis is very important for synthesizing high-quality precursors, in the present invention, the stirring speed energy (Wh/kg) is maintained in the range of 160 to 260 Wh/kg to prevent fines from occurring. While maintaining a certain speed, it was possible to synthesize a precursor with a uniform particle size distribution to ensure excellent performance of the cathode material.

Meanwhile, another factor that affects the total energy received by growing precursor particles is synthesis time. As the synthesis time increases, the amount of energy received by the growing precursor particles increases at the same stirring speed. In other words, the more the particle growth rate is reduced, the more energy applied to the growing precursor particle increases. However, in commercial precursor production processes, precursor growth rate is closely related to productivity. Therefore, in most precursor production processes, the particle growth rate is maintained above a certain level in consideration of productivity. The growth rate of the precursor is very closely related to the overall synthesis time, and the precursor synthesis time is also very closely related to the characteristics of the cathode material. Therefore, it is unreasonable to simply limit the characteristics of the precursor only by the synthesis RPM, and it is reasonable to specify the precursor by the energy applied from the start of synthesis to the end.

Accordingly, the energy index of the present invention sets the kinetic energy value (stirring speed energy) with the concept of including this synthesis time.

Therefore, the energy index (EI) during the synthesis of the precursor according to the present invention is 7,200 ℃ when the synthesis temperature is 45 ℃ (318 K) to 60 ℃ (343 K) and the stirring speed energy (Wh / kg) is 160 to 260 Wh / kg. ·Wh/kg≤ EI ≤ 15,600℃·Wh/kg range.

In addition, when the synthesis temperature is preferably 47°C (320K) to 52°C (345K) and the stirring rate energy (Wh/kg) is 180 to 240 Wh/kg, the energy index (EI) during precursor synthesis is 8,460°C. It is characterized by Wh/kg ≤ EI ≤ 12,480°C·Wh/kg.

In the case of precursors manufactured within the above range, the stacking fault value is reduced, resulting in excellent crystallinity in the positive electrode active material, and secondary batteries using the same have excellent lifespan characteristics at high temperatures.

The positive electrode active material precursor according to the present invention contains nickel-cobalt-manganese represented by the above formula (1) and another metal (A), and the production method is preferably using a coprecipitation reaction.

Specifically, while maintaining the temperature in a range that satisfies the energy index value according to the present invention in a coprecipitation reactor of a certain size (volume), the speed of the stirrer is set at a constant speed in consideration of the size of the coprecipitation reactor and the total amount of precursor to be finally manufactured. Operate the stirrer to have a specific stirring speed energy (Wh/kg).

In this state, an aqueous metal salt solution containing nickel, cobalt, manganese, and additional other metals (A) constituting the precursor is prepared, mixed at a predetermined molar ratio, and reacted at a rate in the range of 150 to 220 kg/hr. Precursor synthesis begins by supplying . The metal salt includes sulfate, nitrate, acetate, halide, hydroxide, etc., and any metal salt may be used as long as it can be prepared in an aqueous solution. In the present invention, sulfate may be preferably used.

At this time, the precipitant and complexing agent are continuously added to the reactor in amounts calculated according to the input rate of the metal in the aqueous metal salt solution.

The precipitant may preferably be an aqueous NaOH solution, and the complexing agent may be an ammonia aqueous solution, an aqueous ammonium sulfate solution, or a mixture thereof.

As the reaction progresses, the stirring speed is adjusted according to the particle growth rate set at the beginning of synthesis, and the precursor is finally synthesized by adjusting the stirring speed of the reactor. The final obtained precursor can be dried at a constant temperature to obtain a nickel-cobalt-manganese composite metal hydroxide precursor.

The particle size of the precursor obtained according to the present invention is characterized in that it is 13.5 to 14.5 ㎛ based on D50. The appropriate particle size distribution of the precursor affects the plasticity characteristics in the cathode material process and the process characteristics during cell manufacturing. Therefore, appropriate particle size distribution of the precursor is very important for the performance of the cathode material. The (D90-D10)/D50 value representing the particle size distribution in the present invention is preferably in the range of 0.30 to 0.55.

In addition, the precursor is mixed with lithium salt (LiOH·H ₂ O) to match the molar ratio of lithium metal to the composite metal in the precursor, and then calcined in an oxygen atmosphere at a constant temperature to obtain a positive electrode active material.

Hereinafter, preferred embodiments of the present invention will be described in detail. The following examples are only for illustrating the present invention, and should not be construed as limiting the scope of the present invention by these examples. In addition, although the examples below are exemplified using specific compounds, it is obvious to those skilled in the art that equivalent effects can be achieved even when equivalents thereof are used.

<Example 1>

Distilled water was added to a coprecipitation reactor with a volume of about 3㎥, nitrogen gas was supplied to remove dissolved oxygen, and the temperature of the reactor was maintained at 48°C to prepare for synthesis. Nickel sulfate, cobalt sulfate, and sulfuric acid were then added while maintaining the stirrer RPM at 240 or higher. The synthesis of the precursor was started by supplying an aqueous metal solution of a certain concentration or higher, mixed with manganese at a molar ratio of 80:12:8, at a rate in the range of 150 to 220 kg/hr. At this time, 25 wt% NaOH was used as a precipitant and 28 wt% NH4OH was used as a complexing agent, and the amount calculated according to the metal input rate was continuously added to the reactor. The stirrer RPM was adjusted according to the particle growth rate set at the beginning of the synthesis, and was finally adjusted to 130 RPM (total stirring speed energy of synthesis = 192.25 Wh/kg) to synthesize a precursor with a Ni _0.8 Co _0.12 Mn _0.08 (OH) ₂ structure. . The precursor thus obtained was dried at 120°C to obtain a nickel cobalt manganese composite metal hydroxide precursor. The final particle size of the synthesized precursor after drying was 14.07 ㎛ based on D50, and the (D90-D10)/D50 value was 0.43.

The precursor obtained in this way was mixed so that the molar ratio of LiOH· and Li/Me (composite metal in the precursor) was 1.05, and then calcined in an oxygen atmosphere at 780°C for 15 hours to obtain a positive electrode active material.

<Example 2>

Precursors and positive electrode active materials were prepared in the same manner as in Example 1, except that the temperature of the reactor was maintained at 50°C and the final stirring speed was 140 RPM (total stirring speed energy of synthesis = 207.77 Wh/kg). did. The final particle size after drying of the synthesized precursor was 13.99 ㎛ based on D50, and the (D90-D10)/D50 value was 0.42. It was.

<Comparative Example 1>

The precursor and positive electrode active material were prepared in the same manner as in Example 1, except that the temperature of the reactor was maintained at 45°C and the mixture was finally stirred at 105 RPM (total stirring speed energy of synthesis = 155.28h/kg). The final particle size of the synthesized precursor after drying was 14.06 ㎛ based on D50, and the (D90-D10)/D50 value was 0.57.

Experimental Example 1: XRD measurement of precursor

The XRD of the precursor synthesized according to Examples 1 and 2 and Comparative Example 1 was measured, and the FWHM value for each crystal plane was shown. Next, Figure 2 shows the FWHM values of the (001) and (101) surfaces of the precursor synthesized according to Examples 1 and 2 and Comparative Example 1, and Figure 3 shows the FWHM values of the (102) surface of Examples 1 and 2 and Comparative Example 1. It's a graph.

Referring to this, it can be seen that as the total energy applied to the reactor during precursor synthesis increases, the FWHM values of the (001) and (101) planes decrease, which means that the crystallinity of the precursor increases. The FWHM of the (001) plane of the precursor is closely related to the FWHM of the (003) plane of the anode material, and the FWHM of the (101) plane of the precursor is closely related to the FWHM of the (104) plane of the anode material. It is known that as the crystallinity increases, the lifespan and high-temperature lifespan of the cathode material increases.

Referring to FIG. 3 showing the FWHM values of the XRD (102) surface of Examples 1, 2, and Comparative Example 1, it can be seen that the higher the input energy, the lower the FWHM of the precursor (102) surface. A decrease in the half width of the (102) plane of the precursor means an increase in the β phase, and accordingly the (003) plane of the cathode material increases, which can be seen as a direct cause of improved high temperature lifespan. This result is shown in FIG. 1 above. This is consistent with the results. In addition, the precursor (102) plane is related to the stacking fault value of the precursor, and as the stacking fault of the precursor decreases, crystallinity increases, so it can be confirmed that the performance of the cathode material is improved.

Experimental Example 2: Measurement of lifetime characteristics of precursor at high temperature

The high-temperature lifespan of the cathode material produced using the precursor synthesized according to Examples 1 and 2 and Comparative Example 1 was tested by manufacturing a coin cell and charging it at 3.0V to 4.3V at a current density of 1C in a constant temperature chamber maintained at 45°C. Discharging was performed and high-temperature lifespan characteristics were measured up to 50 cycles, and the results are shown in Figure 4 and Table 1. The firing process of the cathode material was completely the same in Examples 1 and 2 and Comparative Example 1.

synthesis temperature
(T,℃) Final stirring speed (RPM) Stirring speed energy (E)
Wh/kg Energy Index
(EI, ℃· High temperature life
(%, 50 cycles) Comparative Example 1 45 105 155.28 6987.6 84.7 Example 1 48 130 192.25 9,228.0 87.3 Example 2 50 140 207.77 10,388.5 89.1

Referring to FIG. 4, it can be seen that the high-temperature lifespan of each cathode material increases as the cycle progresses. Therefore, it can be seen that the high-temperature lifespan of the cathode material made from a precursor synthesized at a high energy index (EI) is dramatically improved during precursor synthesis.

In addition, referring to the results in Table 1, as in the present invention, the value of the energy index (EI), defined as the product of the synthesis temperature (℃) and the stirring rate energy (Wh/kg), is 7,200 ℃·Wh/kg ≤ EI In the case of active materials using precursors manufactured under conditions in the range of ≤ 15,600℃·Wh/kg (Examples 1 and 2), it can be seen that the high-temperature lifespan characteristics are excellent, and the larger the applied energy index value, the better the lifespan characteristics at high temperatures. Able to know. However, in the case of Comparative Example 1, where the value of the energy index (EI), defined as the product of the synthesis temperature (°C) and the stirring rate energy (Wh/kg), is less than this, it can be seen that the high temperature lifespan is poor.

Claims (6)

It is characterized by being manufactured under conditions in which the energy index (EI), defined as the product of the synthesis temperature (℃) and the stirring speed energy (Wh/kg), is in the range of 7,200 ℃·Wh/kg ≤ EI ≤ 15,600℃·Wh/kg A positive electrode active material precursor for a secondary battery represented by the following formula 1:
Formula 1
Ni _(1-xyz) Co _x Mn _y A _z (OH) ₂
In the above formula, A includes one or more elements selected from the group consisting of Al, B, Ba, Ce, Cr, F, Li, Mo, P, Sr, Ti, and Zr, and x, y, and z are each 0.2≥x ≥0, 0.1≥y≥0, 0.05≥z≥0 are satisfied. According to claim 1,
A positive electrode active material precursor, characterized in that the particle size of the precursor is 13.5 to 14.5 ㎛ based on D50, and the (D90-D10)/D50 value representing the particle size distribution is 0.30 to 0.55. According to claim 1,
A positive active material precursor for a secondary battery, wherein the synthesis temperature satisfies a value between 45°C (318K) and 60°C (343K). According to claim 1,
The stirring speed energy is the kinetic energy applied to the synthesis system through stirring from the start of synthesis to the end, and its range is 160 to 260 Wh as the total electrical energy for the final obtained precursor production (kg). A positive active material precursor for a secondary battery. The energy index (EI), defined as the product of the synthesis temperature (℃) and the stirring speed energy (Wh/kg), is manufactured under conditions in the range of 7,200 ℃·Wh/kg ≤ EI ≤ 15,600 ℃·Wh/kg. A method for producing a positive electrode active material precursor for a secondary battery represented by the following Chemical Formula 1, comprising:
Formula 1
Ni _(1-xyz) Co _x Mn _y A _z (OH) ₂
In the above formula, A includes one or more elements selected from the group consisting of Al, B, Ba, Ce, Cr, F, Li, Mo, P, Sr, Ti, and Zr, and x, y, and z are each 0.2≥x ≥0, 0.1≥y≥0, 0.05≥z≥0 are satisfied. A cathode active material for a lithium secondary battery obtained by sintering the precursor according to claim 1.