WO2014046405A2 - Anode active material, nonaqueous lithium secondary battery comprising same, and preparation method thereof - Google Patents

Abstract

The present invention relates to an anode active material, a nonaqueous lithium secondary battery comprising the same, and a preparation method thereof, wherein a surface of a carbon-based material is modified without using an electrolyte additive and the reactivity and structural stability of the surface are improved, thereby ensuring lifetime characteristics without deteriorating charge/discharge efficiency and high rate characteristics and enhancing high temperature storage characteristics and low temperature characteristics when the carbon-based material is applied as an anode active material for a nonaqueous lithium secondary battery. According to the present invention, the anode active material comprises a carbon-based material; and a coating layer comprising phosphorus (P) or boron (B) formed on the surface of the carbon-based material, wherein the coating layer comprises a phosphorus (P) or boron (B) compound through treatment with phosphoric acid (H₃PO₄) or boric acid (H₃BO₃).

Description

Anode Active Material, Non-aqueous Lithium Secondary Battery Having It and Manufacturing Method Thereof

The present invention relates to a non-aqueous lithium secondary battery and a manufacturing method thereof, and more particularly, a negative electrode active material having a surface film containing phosphorus or boron formed on the surface of a carbon-based material that is applied as a negative electrode active material of a lithium secondary battery And a non-aqueous lithium secondary battery having the same, and a method for producing the same.

With the spread of portable small electric electronic devices, new secondary batteries such as nickel-metal hydride batteries and lithium secondary batteries have been actively developed.

Among them, a lithium secondary battery is a battery in which metal lithium is used as a negative electrode active material and a nonaqueous solvent is used as an electrolyte. Since lithium is a metal with a high tendency to ionize, development of a battery with high energy density is possible because of high voltage expression. Lithium secondary batteries using lithium metal as a negative electrode active material have been used for a long time as next generation batteries.

When the carbon-based material is applied to the lithium secondary battery as the negative electrode active material, the charge and discharge potential of lithium is lower than the stable range of the existing non-aqueous electrolyte, so that the decomposition reaction of the electrolyte occurs during charge and discharge. As a result, a film is formed on the surface of the carbon-based negative electrode active material. That is, before lithium ions are intercalated into a carbon-based material, the electrolyte decomposes to form a film on the electrode surface. The film has a property of passing lithium ions but a property of blocking electrons. Once the film is formed, electrolyte decomposition due to electron transfer between the electrode and the electrolyte is suppressed, and only insertion and de-intercalation of lithium ions are selectively possible. Such a coating is called SEI (Solid Electrolyte Interface or Solid Electrolyte Interphase).

The film thus formed is decomposed repeatedly through repeated charging and discharging processes, and the formation of an unstable film results in low initial charge and discharge efficiency and deterioration of life characteristics and high rate of current lithium secondary batteries using a carbon-based material as a negative electrode active material. It is pointed out as the root cause of deterioration.

For this reason, carbon-based negative electrode using an electrolyte additive having a higher decomposition potential than conventional carbonate-based electrolytes such as various VC (vinylene carbonate) and FEC (fluoroethylene carbonate) to secure long life characteristics of non-aqueous lithium secondary battery using carbon-based materials A method of stabilizing the surface of an active material has been proposed.

However, these electrolyte additives can improve the life characteristics, but the problem of deterioration in capacity, high rate characteristics and charge and discharge efficiency could not be solved.

Therefore, the research to induce stable film formation by modifying the surface of the carbon-based material in a variety of ways are in progress, but the technology that shows superior characteristics than using the existing additives has not been developed yet.

Therefore, an object of the present invention is to modify the surface of the carbon-based material without using an electrolyte additive and improve the surface reactivity and structural stability, when applied as a negative electrode active material of a non-aqueous lithium secondary battery, long life without deterioration of charge and discharge efficiency and high rate characteristics The present invention provides a negative electrode active material, a non-aqueous lithium secondary battery having the same, and a method of manufacturing the same, which can secure the characteristics and improve the high temperature storage characteristics and the low temperature characteristics.

In order to achieve the above object, the present invention provides a negative electrode active material for a non-aqueous lithium secondary battery comprising a carbon-based material and a coating layer containing phosphorus (P) or boron (B) formed on the surface of the carbon-based material.

In the negative electrode active material according to the present invention, the coating layer, the phosphorus (P) or the boron (B) formed on the surface of the carbon-based material through phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) treatment It contains a compound containing.

In the negative electrode active material according to the present invention, in the coating layer, the amount of the phosphorus (P) or the boron (B) may be 10 wt% or less.

In the anode active material according to the present invention, the phosphorus (P) having a 2p peak of 131 ~ 135eV is present on the surface of the carbon-based material through XPS analysis.

In the negative electrode active material according to the present invention, boron (B) having a 1s peak of 190 to 197 eV is present on the surface of the carbonaceous material through XPS analysis.

In the negative electrode active material according to the present invention, the coating layer may be uniformly formed on the surface of the carbonaceous material.

In the negative electrode active material according to the present invention, the carbonaceous material may include at least one of artificial graphite, natural graphite, graphitized carbon fiber, graphitized mesocarbon microbead, petroleum coke, resinous body, carbon fiber and pyrolytic carbon. have.

In the negative electrode active material according to the present invention, the carbonaceous material may have a particle size of 20 μm or less.

The present invention also provides a non-aqueous lithium secondary battery comprising a negative electrode having the negative electrode active material described above.

The present invention also provides a negative electrode active material for a non-aqueous lithium secondary battery comprising the steps of preparing a carbon-based material, and forming a coating layer containing phosphorus (P) or boron (B) on the surface of the carbon-based material It provides a manufacturing method.

In the method of manufacturing a negative electrode active material according to the present invention, the coating step is a mixing step of mixing the phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) solution to the carbon-based material, and the phosphoric acid (H ₃ PO ₄ ) or a drying step of drying the carbonaceous material mixed with a solution of boric acid (H ₃ BO ₃ ), and heat treating the dried carbonaceous material to form phosphorus (P) or boron (B) on the surface of the carbonaceous material. It may comprise a heat treatment step of forming a coating layer containing).

In the method of manufacturing a negative electrode active material according to the present invention, in the mixing step, a solution containing 5 wt% or less of phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) may be mixed with the carbonaceous material.

In the manufacturing method of the negative electrode active material according to the present invention, the drying step may be carried out at room temperature ~ 100 ℃.

In the manufacturing method of the negative electrode active material according to the present invention, the heat treatment step may be performed for 1 to 10 hours in an inert gas atmosphere of 500 ~ 1000 ℃.

And in the method of manufacturing a negative electrode active material according to the invention, the coating layer is the phosphorus (P) or the boron formed on the surface of the carbon-based material through phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) treatment It may be a compound containing (B).

According to the present invention, phosphorus (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) is treated on the surface of a carbon-based material used as a negative electrode active material of a non-aqueous lithium secondary battery without using a carbonate electrolyte additive. By forming the coating layer containing P) or boron (B), formation of a more stable film on the surface of a carbonaceous material can be induced.

In addition, by improving the reactivity and structural stability of the surface of the negative electrode active material through a stable coating, when used as a negative electrode active material of a non-aqueous lithium secondary battery, it is possible to secure long life characteristics without deterioration of high rate characteristics, and to improve high temperature storage characteristics and low temperature characteristics. Can be.

1 is a flow chart according to a method of manufacturing a negative active material for a non-aqueous lithium secondary battery in which a coating layer containing phosphorus (P) or boron (B) according to the present invention is formed.

2 is a graph showing the results of X-ray diffraction (XRD) analysis of the negative electrode active material according to the Examples and Comparative Examples of the present invention.

3 and 4 are scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) photographs showing negative active materials according to Examples 1 and 2 of the present invention.

5 and 6 are graphs showing the results of EDS and X-ray Photoelectron Spectroscopy (XPS) analysis of the negative electrode active materials according to Examples 1 and 2 of the present invention.

7 is a graph showing the life characteristics of the non-aqueous lithium secondary battery using the negative electrode active material according to the Examples and Comparative Examples of the present invention.

FIG. 8 is a graph comparing discharge characteristics according to rates of a non-aqueous lithium secondary battery using a negative electrode active material according to Examples and Comparative Examples of the present invention.

9 and 10 are graphs comparing the high-temperature storage characteristics of the non-aqueous lithium secondary battery using the negative electrode active material according to the embodiment of the present invention and the comparative example.

11 is a graph comparing low-temperature characteristics of the non-aqueous lithium secondary battery using the negative electrode active material according to the Examples and Comparative Examples of the present invention.

In the following description, only parts necessary for understanding the embodiments of the present invention will be described, it should be noted that the description of other parts will be omitted so as not to distract from the gist of the present invention.

The terms or words used in the specification and claims described below should not be construed as being limited to the ordinary or dictionary meanings, and the inventors are appropriate to the concept of terms in order to explain their invention in the best way. It should be interpreted as meanings and concepts in accordance with the technical spirit of the present invention based on the principle that it can be defined. Therefore, the embodiments described in the present specification and the configuration shown in the drawings are only preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, and various equivalents may be substituted for them at the time of the present application. It should be understood that there may be variations and variations.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention.

The negative active material for a non-aqueous lithium secondary battery according to the present invention includes a carbon-based material and a coating layer containing phosphorus (P) or boron (B) formed on the surface of the carbon-based material.

The carbon-based material may be at least one selected from materials consisting of amorphous carbon such as artificial graphite, natural graphite, graphitized carbon fiber, graphitized mesocarbon microbead, petroleum coke, resin plastic, carbon fiber, and pyrolytic carbon. The carbon-based material has a particle size of 20 µm or less, preferably 7 µm or less.

Phosphorus (P) or boron (B) used as a coating layer may be introduced through phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) treatment. In this case, phosphorus (P) and boron (B) is present in the form of a compound by chemically or physically bonding with oxygen or a material forming a carbon-based material on the surface of the carbon-based material. Therefore, the coating layer contains a compound containing phosphorus (P) and boron (B).

This coating layer may be formed uniformly on the surface of the carbon-based material. At this time, the amount of phosphorus (P) or boron (B) is 10wt% or less, preferably 5wt% or less.

Such a method of manufacturing the negative active material of the non-aqueous lithium secondary battery according to the present invention will be described with reference to FIG. 1. 1 is a flow chart according to a method of manufacturing a negative active material for a non-aqueous lithium secondary battery in which a coating layer containing phosphorus (P) or boron (B) according to the present invention is formed.

Referring to FIG. 1, the method of preparing a negative active material of a non-aqueous lithium secondary battery according to the present invention includes preparing a carbonaceous material (S10), and phosphorus (P) or boron (B) on the surface of the carbonaceous material. It includes a coating step (S10 ~ S50) to form a coating layer containing.

First, prepare a carbon-based material in step S10. In this case, the carbon-based material may have an average particle size (particle size) of 20 μm or less. Although various materials can be used as the carbon-based material, it is preferable to use a graphite-based material in consideration of the combination with phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ).

Next, a phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) solution is prepared in step S20. For example, phosphoric acid (H ₃ PO ₄₎ or boric acid (H ₃ BO ₃₎ may be less than 5wt% by dissolving in deionized water to prepare a phosphoric acid (H ₃ PO ₄₎ or boric acid (H ₃ BO ₃₎ solution.

Next, phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) solution is mixed with the carbonaceous material in step S30. For example, up to 5 wt% phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) solution may be mixed with the carbonaceous material.

Subsequently, the carbon-based material mixed with phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) solution is dried in step S40. Drying may be carried out at a temperature of room temperature ~ 100 ℃, for example, drying may be carried out at 100 ℃ for 2 hours.

And by heat-treating the carbon-based material dried in step S50 to form a coating layer of phosphorus (P) or boron (B) on the surface of the carbon-based material, it is possible to obtain the negative electrode active material according to the present invention. Heat treatment may be performed for 1 to 10 hours in an inert gas atmosphere of 500 ~ 1000 ℃, for example, may be performed for 2 hours in a nitrogen gas atmosphere of 800 ℃.

As described above, the anode active material according to the present invention is phosphorus (P) or boron (B) by treating phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) on the surface of the carbonaceous material without using a carbonate electrolyte additive. By forming a coating layer containing, a more stable coating (SEI) can be induced on the surface of the carbonaceous material.

In addition, the stable coating improves the reactivity and structural stability of the surface of the negative electrode active material, and when applied to the negative electrode active material of the non-aqueous lithium secondary battery, it is possible to secure long life characteristics without deterioration of high rate characteristics, and improve high temperature storage characteristics and low temperature characteristics. can do.

In order to evaluate the long life characteristics, high rate characteristics, high temperature storage characteristics, and low temperature characteristics of the non-aqueous lithium secondary battery to which the negative electrode active material according to the present invention was applied, a negative active material and a non-aqueous lithium secondary battery using the same were prepared as follows. At this time, in the case of the embodiment, natural graphite having a coating layer formed on the surface was used as the negative electrode active material. In the comparative example, natural graphite not surface-treated with the negative electrode active material and natural graphite surface-treated with deionized water were used. And since the manufacturing of the non-aqueous lithium secondary battery according to the Examples and Comparative Examples except for the negative electrode active material proceeds in the same way, will be described with reference to the manufacturing method of the non-aqueous lithium secondary battery according to the embodiment.

In order to introduce phosphorus (P) or boron (B) on the surface of natural graphite among carbonaceous materials, 2 wt% of phosphoric acid (H ₃ PO ₄ ) and boric acid (H ₃ BO ₃ ) are dissolved in deionized water, respectively. After coating uniformly to, and finally, the negative electrode active material for a non-aqueous lithium secondary battery containing a phosphorus (P) or boron (B) on the surface by heat treatment at 800 ℃.

As shown in Table 1, Comparative Example 1 used untreated natural graphite having a particle size of 7 μm or less in the carbon-based material. Example 1 is a material treated with phosphoric acid (H ₃ PO ₄ ) on the surface of the natural graphite according to Comparative Example 1, Example 2 is a natural graphite treated with boric acid (H ₃ BO ₃ ) on the surface. Comparative Example 2 is a natural graphite that was subjected to the same heat treatment using only deionized water instead of phosphoric acid (H ₃ PO ₄ ) and boric acid (H ₃ BO ₃ ) in order to confirm the heterogeneous element treatment effect.

Table 1

	Base material	Surface treatment	content	Drying temperature	Heat treatment temperature
Comparative Example 1	Natural graphite	-	-	-	-
Comparative Example 2	Natural graphite	Water	2wt%		100 ℃	800 ℃
Example 1	Natural graphite	H 3 PO 4	2wt%	100 ℃	800 ℃
Example 2	Natural graphite	H 3 BO 3	2wt%	100 ℃	800 ℃

2 is a graph showing the results of X-ray diffraction (XRD) analysis of the negative electrode active material according to the Examples and Comparative Examples of the present invention.

As shown in FIG. 2, it can be seen that XRD analysis shows that Comparative Examples 1, 1 and 2 are substantially the same waveform. That is, when compared with natural graphite according to Comparative Example 1 on the surface of the natural graphite base material after phosphoric acid (H ₃ PO ₄ ) and boric acid (H ₃ BO ₃ ) treatment, no structural change or impurity formation was observed. It can be seen that the change in surface area is also slight.

As in Examples 1 and 2, natural graphite surface-treated with phosphoric acid (H ₃ PO ₄ ) and boric acid (H ₃ BO ₃ ) has phosphorus (P) and boron (B) on its surface. It can be confirmed through the results of analysis of energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) of 6. 3 and 4 are scanning electron microscope (SEM) and EDS photographs showing negative active materials according to Examples 1 and 2 of the present invention. 5 and 6 are graphs showing the results of EDS and XPS analysis of the negative electrode active materials according to Examples 1 and 2 of the present invention. 3 shows Example 1, FIG. 4 shows Example 2, (a) is a SEM photograph, and (b) is an EDS photograph.

As shown in FIG. 3 to FIG. 6, it was confirmed that phosphorus (P) and boron (B) were uniformly present on the surface of natural graphite as a result of EDS and XPS analysis. As a result of element mapping using EDS on the surface of natural graphite treated with 2 wt% phosphoric acid (H ₃ PO ₄ ) and boric acid (H ₃ BO ₃ ), respectively, Example 1 shows phosphorus (P) on the surface. 0.46 wt%, Example 2 was confirmed to contain 0.45 wt% of boron (B). Phosphorus (P) and boron (B) remaining on the surfaces of Examples 1 and 2 were also verified by XPS analysis.

In Example 1, it was confirmed that 131 to 135 eV, which is a 2p peak of phosphorus (P), was clearly present on the surface. In Example 2, it was confirmed that 190-197 eV, which is the 1s peak of boron (B), was clearly present. This suggests that phosphorus (P) and boron (B) present on the surface of natural graphite form a specific bond with carbon of natural graphite. Phosphorus (P) is mainly present in the form of 5 + (134.5 eV), boron (B) was confirmed to exist mainly in the form of 3 + (193.1 eV).

A non-aqueous lithium secondary battery was manufactured using the negative electrode active materials according to the Examples and Comparative Examples as follows. That is, 96 wt% of the negative electrode active material, the binder SBR, and the thickener CMC were 2 wt%, respectively, and a slurry was prepared using water as a solvent. The slurry was coated on copper foil and then dried to prepare an electrode. The loading level of the electrode is 5 mg / cm ² , the mixture density is 1.5 g / cc. Electrochemical properties were evaluated after fabrication of half cell using lithium metal counter electrode, and 1M LiPF6 in EC / EMC was used as electrolyte.

As a result of evaluating the long life characteristics of the non-aqueous lithium secondary battery according to the embodiment and the comparative example is shown in FIG. 7 is a graph showing the life characteristics of the non-aqueous lithium secondary battery using the negative electrode active material according to the Examples and Comparative Examples of the present invention.

The life evaluation of the comparative examples and examples is 0.01 ~ 2.0 V vs. After charging and discharging three times at a constant current of 72 mA / g in the Li / Li ⁺ potential region, charging and discharging was performed 50 times at a constant current of 180 mA / g, and the results are shown in FIG. 7.

Referring to FIG. 7, the difference in capacity and life characteristics of Comparative Examples 1 and 2 is insignificant, but Examples 1 and 2 treated with phosphoric acid (H ₃ PO ₄ ) and boric acid (H ₃ BO ₃ ) have improved capacity and life characteristics. You can see that. The introduction of phosphorus (P) and boron (B) on the surface of the natural graphite, it is believed that the life characteristics are improved by inducing a more stable film formation on the surface of the natural graphite.

As a result of evaluating the discharge characteristics for each rate of the non-aqueous lithium secondary battery according to the Examples and Comparative Examples are shown in FIG. FIG. 8 is a graph comparing discharge characteristics according to rates of a non-aqueous lithium secondary battery using a negative electrode active material according to an embodiment of the present invention and a comparative example.

Referring to FIG. 8, the charging was performed at a constant current of 72 mA / g, and the discharge was 72 mA / g (0.2C), 180 mA / g (0.5C), 360 mA / g (1.0C), 1080 mA / g (3.0C), 1800 mA / g (5.0C) constant current was carried out, the results are shown as retention for 0.2C capacity. Phosphoric acid (H ₃ PO ₄ ) and boric acid (H ₃ BO ₃ ) treated Examples 1 and 2 can be seen to show improved rate-specific properties compared to Comparative Examples 1 and 2.

The results of evaluating the high temperature storage characteristics of the non-aqueous lithium secondary battery according to the embodiment and the comparative example are as shown in FIGS. 9 and 10. 9 and 10 are graphs comparing the high-temperature storage characteristics of the non-aqueous lithium secondary battery using the negative electrode active material according to the embodiment of the present invention and the comparative example.

9 and 10, after comparing the discharge capacity measured at a constant current of 72 mA / g after storing the cell at 80 ° C. for 48 hours in a charged state, and maintaining the discharge capacity after recharging at room temperature, compared to Comparative Example 1 Examples 1 and 2 treated with phosphoric acid (H ₃ PO ₄ ) and boric acid (H ₃ BO ₃ ) show a small self-discharge rate due to high temperature storage, and it can be seen that the recovery capacity is improved at room temperature charging.

And the result of evaluating the low-temperature characteristics of the non-aqueous lithium secondary battery according to the embodiment and the comparative example is as shown in FIG. 11 is a graph comparing low-temperature characteristics of the non-aqueous lithium secondary battery using the negative electrode active material according to the embodiment of the present invention and the comparative example.

Referring to Figure 11, after 24 hours storage at -20 ℃ after 6 minutes charging with a constant current of 360 mA / g was compared OCV (open circuit voltage) behavior. In Examples 1 and 2 treated with phosphoric acid (H ₃ PO ₄ ) and boric acid (H ₃ BO ₃ ), it was confirmed that the recovery time was faster after lithium electrodeposition compared to 1, which improved the thermal stability of natural graphite. It means.

On the other hand, the embodiments disclosed in the specification and drawings are merely presented specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims (15)

1. Carbon-based materials;

   A coating layer containing phosphorus (P) or boron (B) formed on the surface of the carbonaceous material;

   A negative electrode active material for a non-aqueous lithium secondary battery comprising a.
2. The method of claim 1, wherein the coating layer,

   A non-aqueous system comprising a compound containing phosphorus (P) or boron (B) formed on the surface of the carbonaceous material through phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) treatment Anode active material for lithium secondary battery.
3. The method of claim 2, wherein in the coating layer,

   The amount of the phosphorus (P) or the boron (B) is 10 wt% or less, the negative active material for a non-aqueous lithium secondary battery.
4. The method of claim 3,

   The negative active material for a non-aqueous lithium secondary battery, characterized in that the phosphorus (P) having a 2p peak of 131 ~ 135eV on the surface of the carbon-based material through XPS analysis.
5. The method of claim 4, wherein

   An anode active material for a non-aqueous lithium secondary battery, wherein the boron (B) having a 1s peak of 190 to 197 eV is present on the surface of the carbonaceous material through XPS analysis.
6. The method of claim 2,

   The coating layer is a negative active material for a non-aqueous lithium secondary battery, characterized in that formed on the surface of the carbon-based material uniformly.
7. The method of claim 1, wherein the carbon-based material,

   A negative active material for a non-aqueous lithium secondary battery, comprising at least one of artificial graphite, natural graphite, graphitized carbon fiber, graphitized mesocarbon microbead, petroleum coke, resin plastic, carbon fiber, and pyrolytic carbon.
8. The method of claim 7, wherein

   The carbonaceous material is a negative active material for a non-aqueous lithium secondary battery, characterized in that the particle size is 20㎛ or less.
9. Non-aqueous lithium secondary battery comprising a negative electrode having a negative electrode active material according to any one of claims 1 to 8.
10. Preparing a carbonaceous material;

    A coating step of forming a coating layer containing phosphorus (P) or boron (B) on the surface of the carbonaceous material;

    Method for producing a negative active material for a non-aqueous lithium secondary battery comprising a.
11. The method of claim 10, wherein the coating step,

    Mixing the phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) solution with the carbonaceous material;

    A drying step of drying the carbonaceous material in which the phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) solution is mixed;

    Heat-treating the dried carbon-based material to form a coating layer containing phosphorus (P) or boron (B) on the surface of the carbon-based material;

    Method for producing a negative active material for a non-aqueous lithium secondary battery comprising a.
12. The method of claim 11, wherein in the mixing step

    A method for producing a negative active material for a non-aqueous lithium secondary battery, characterized in that the solution containing 5 wt% or less of phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) to the carbon-based material.
13. The method of claim 12, wherein the drying step,

    Method for producing a negative active material for a non-aqueous lithium secondary battery, characterized in that carried out at room temperature ~ 100 ℃.
14. The method of claim 13, wherein the heat treatment step,

    Method for producing a negative active material for a non-aqueous lithium secondary battery, characterized in that performed for 1 to 10 hours in an inert gas atmosphere of 500 ~ 1000 ℃.
15. The method of claim 11, wherein the coating layer,

    Non-aqueous lithium secondary, characterized in that the compound containing the phosphorus (P) or boron (B) formed on the surface of the carbon-based material through phosphoric acid (H ₃ PO ₄ ) or boric acid (H ₃ BO ₃ ) treatment The manufacturing method of the negative electrode active material for batteries.

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