CN103278760B - Power-type lithium ion battery method for estimating remaining capacity under different temperatures environment - Google Patents

Abstract

A method for estimating the remaining power of a power type lithium ion battery under different temperature environments, the invention relates to the field of estimating the remaining power of a power type lithium ion battery. The invention aims to solve the problem that the existing method for estimating the remaining power of the battery does not consider the influence of temperature on the remaining power of the battery. 1. Lithium-ion batteries are subjected to six rate discharge tests under six temperature conditions; 2. Select 10C rate as the highest discharge current and 1/3C rate as the lowest discharge current to obtain the Peukert coefficients K and n of the six temperature conditions ; 3. Carry out curve fitting on six points to obtain a fitting formula with T as the independent variable and k as the dependent variable; 4. Carry out curve fitting on the six points to obtain T as the independent variable and n as the dependent variable 5. The available capacity formula; 6. Bring C _{ava, I, T} into the battery remaining capacity formula (4) Estimate the remaining capacity of the power lithium-ion battery under different temperature environments. The invention is applied to the field of estimation of remaining battery power.

Description

Method for Estimating Residual Capacity of Power Lithium-ion Batteries in Different Temperature Environments

technical field

The invention relates to the field of estimating the remaining power of a power type lithium ion battery.

Background technique

The research on the remaining power of the battery mainly considers the application under normal temperature conditions, and there are few studies on the estimation of the remaining power of the battery under different temperature environments. The traditional Peukert equation is a way to estimate the remaining capacity of the battery, but it also does not fully consider the temperature effect.

The most famous method for estimating the available capacity of the battery is the Peukert equation proposed by Peukert in 1897, which describes the relationship between the available capacity of the battery and the discharge current, and has been widely accepted. The formula is:

C _ava,I =K*I ^(1-n)

Among them, K and n are constants, called Peukert coefficients K and n.

However, this formula does not take into account the role of temperature in the estimate of usable capacity.

Reference Document 1 (Research on Estimation Method of Remaining Power of Ni-MH Batteries for Electric Vehicles, Wu Guoliang, China Doctoral Dissertations Full-text Database Engineering Science and Technology Series II, Issue 08, 2011, Page C035-8, August 15, 2011), However, the fitting accuracy of the quadratic function of the Peukert equation coefficient of the Ni-MH battery is low, and it cannot truly reflect the SOC value.

Contents of the invention

The present invention aims to solve the problem that the quadratic function fitting of the Peukert equation coefficient of the Ni-MH battery in the existing method for estimating the remaining battery power is low in accuracy and fails to truly reflect the SOC value, and provides a power type lithium-ion battery under different temperature environments. Method for estimating remaining battery power.

The method for estimating the remaining power of a power type lithium-ion battery under different temperature environments is implemented in the following steps:

1. Under the temperature condition of T1=35℃, the lithium-ion battery is subjected to six rate discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery is tested at 10C, 7C, 5C, 3C, The discharge capacities of six rates of 1C and 1/3C are recorded as C _10C1 , C _7C1 , C 5C1 , C _3C1 , C _1C1 , and C _{1/3C1 ;}

Under the temperature condition of T2=25°C, the lithium-ion battery was subjected to six rate discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery was tested at 10C, 7C, 5C, 3C, 1C and The discharge capacity of six rates of 1/3C is recorded as C _10C2 , C _7C2 , C _5C2 , C _3C2 , C _1C2 , and C _1/3C2 ;

Under the temperature condition of T3=10°C, the lithium-ion battery was subjected to six discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery was tested at 10C, 7C, 5C, 3C, 1C and The discharge capacity of six rates of 1/3C is recorded as C _10C3 , C _7C3 , C _5C3 , C _3C3 , C _1C3 , and C _1/3C3 ;

Under the temperature condition of T4=0°C, the lithium-ion battery was subjected to six discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery was tested at 10C, 7C, 5C, 3C, 1C and The discharge capacity of six rates of 1/3C is recorded as C _10C4 , C _7C4 , C _5C4 , C _3C4 , C _1C4 , and C _1/3C4 ;

Under the temperature condition of T5=-10°C, the lithium-ion battery was subjected to six discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery was tested at 10C, 7C, 5C, 3C and 1C. and 1/3C six rates of discharge capacity, respectively recorded as C _10C5 , C _7C5 , C _5C5 , C _3C5 , C _1C5 , C _1/3C5 ;

Under the temperature condition of T6=-15℃, the lithium-ion battery was subjected to six rate discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery was tested at 10C, 7C, 5C, 3C and 1C. and 1/3C six rates of discharge capacity, recorded as C _10C6 , C _7C6 , C _5C6 , C _3C6 , C _1C6 , C _1/3C6 ;

2. Choose 10C rate as the highest discharge current, and 1/3C rate as the lowest discharge current:

Taking I _10C1 , I _1/3C1 , C _10C1 and C _1/3C1 as calculation data, the Peukert coefficients at T1=35°C are obtained as k1 and n1;

Taking I _10C2 , I _1/3C2 , C _10C2 and C _1/3C2 as calculation data, the Peukert coefficients k2 and n2 at T2=25°C are obtained;

Taking I _10C3 , I _1/3C3 , C _10C3 and C _1/3C3 as calculation data, the Peukert coefficients k3 and n3 at T3=10°C are obtained;

Taking I _10C4 , I _1/3C4 , C _10C4 and C _1/3C4 as calculation data, the Peukert coefficients k4 and n4 at T4=0°C are obtained;

Taking I _10C5 , I _1/3C5 , C _10C5 and C _1/3C5 as calculation data, the Peukert coefficients k5 and n5 at T5=-10°C are obtained;

Taking I _10C6 , I _1/3C6 , C _10C6 and C _1/3C6 as calculation data, the Peukert coefficients k6 and n6 at T6=-15°C are obtained;

3. Taking T as the horizontal axis and k-axis as the vertical axis, for six points (T1, k ₁ ), (T2, k ₂ ), (T3, k ₃ ),

(T4, k ₄ ), (T5, k ₅ ) and (T6, k ₆ ) perform curve fitting, and use the least square method to obtain a fitting formula with T as the independent variable and k as the dependent variable,

k(T)＝a ₄ T ⁴ +a ₃ T ³ +a ₂ T ² +a ₁ T+a ₀ (1)

4. With T as the horizontal axis and n axis as the vertical axis, for six points (T1, n ₁ ), (T2, n ₂ ), (T3, n ₃ ),

(T4, n ₄ ), (T5, n ₅ ) and (T6, n ₆ ) carry out curve fitting, and use the least square method to obtain a fitting formula with T as the independent variable and n as the dependent variable,

n(T)=b ₄ T ⁴ +b ₃ T ³ +b ₂ T ² +b ₁ T+b ₀ (2)

5. The available capacity formula is:

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; ava</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; I</span>}}^{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; I</span>}}^{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; \&SubsetEqual;</span><span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; C</span>}}\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; C</span>}}\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; ]</span>$

(3) Sixth, bring C _{ava, I, T} into the battery remaining power formula (4) Estimate the remaining power of the power lithium-ion battery under different temperature environments:

$\mathrm{<span\; class="notranslate">\; SOC</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; SOC</span>}}_{\mathrm{<span\; class="notranslate">\; ini</span>}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; dis</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; ava</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Among them, SOCini is the initial SOC, Cdis is the discharge capacity, and Cava is the available capacity.

Effect of the present invention:

The present invention conducts discharge experiments at different rates for power lithium-ion batteries under different temperature conditions, establishes and overturns the Peukert equation considering temperature, thereby estimating the available capacity of the battery under different temperature environments, and establishing the power under different temperature environments A method for estimating the remaining capacity of a lithium-ion battery, thereby estimating the remaining capacity of the battery under different temperature environments. The invention realizes the estimation of the remaining power of the power type lithium ion battery under different temperature environments.

Description of drawings

Fig. 1 is the flow chart of the present invention.

Detailed ways

Specific implementation mode 1: The method for estimating the remaining power of a power type lithium-ion battery under different temperature environments in this implementation mode is implemented according to the following steps:

1. Under the temperature condition of T1=35℃, the lithium-ion battery is subjected to six rate discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery is tested at 10C, 7C, 5C, 3C, The discharge capacities of six rates of 1C and 1/3C are recorded as C _10C1 , C _7C1 , C 5C1 , C _3C1 , C _1C1 , and C _{1/3C1 ;}

Under the temperature condition of T2=25°C, the lithium-ion battery was subjected to six rate discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery was tested at 10C, 7C, 5C, 3C, 1C and The discharge capacity of six rates of 1/3C is recorded as C _10C2 , C _7C2 , C _5C2 , C _3C2 , C _1C2 , and C _1/3C2 ;

Under the temperature condition of T3=10°C, the lithium-ion battery was subjected to six discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery was tested at 10C, 7C, 5C, 3C, 1C and The discharge capacity of six rates of 1/3C is recorded as C _10C3 , C _7C3 , C _5C3 , C _3C3 , C _1C3 , and C _1/3C3 ;

Under the temperature condition of T4=0°C, the lithium-ion battery was subjected to six discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery was tested at 10C, 7C, 5C, 3C, 1C and The discharge capacity of six rates of 1/3C is recorded as C _10C4 , C _7C4 , C _5C4 , C _3C4 , C _1C4 , and C _1/3C4 ;

Under the temperature condition of T5=-10°C, the lithium-ion battery was subjected to six discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery was tested at 10C, 7C, 5C, 3C and 1C. and 1/3C six rates of discharge capacity, respectively recorded as C _10C5 , C _7C5 , C _5C5 , C _3C5 , C _1C5 , C _1/3C5 ;

Under the temperature condition of T6=-15℃, the lithium-ion battery was subjected to six rate discharge tests of 10C, 7C, 5C, 3C, 1C and 1/3C, and the lithium-ion battery was tested at 10C, 7C, 5C, 3C and 1C. and 1/3C six rates of discharge capacity, recorded as C _10C6 , C _7C6 , C _5C6 , C _3C6 , C _1C6 , C _1/3C6 ;

2. Choose 10C rate as the highest discharge current, and 1/3C rate as the lowest discharge current:

Taking I _10C1 , I _1/3C1 , C _10C1 and C _1/3C1 as calculation data, the Peukert coefficients at T1=35°C are obtained as k1 and n1;

Taking I _10C2 , I _1/3C2 , C _10C2 and C _1/3C2 as calculation data, the Peukert coefficients k2 and n2 at T2=25°C are obtained;

Taking I _10C3 , I _1/3C3 , C _10C3 and C _1/3C3 as calculation data, the Peukert coefficients k3 and n3 at T3=10°C are obtained;

Taking I _10C4 , I _1/3C4 , C _10C4 and C _1/3C4 as calculation data, the Peukert coefficients k4 and n4 at T4=0°C are obtained;

Taking I _10C5 , I _1/3C5 , C _10C5 and C _1/3C5 as calculation data, the Peukert coefficients k5 and n5 at T5=-10°C are obtained;

Taking I _10C6 , I _1/3C6 , C _10C6 and C _1/3C6 as calculation data, the Peukert coefficients k6 and n6 at T6=-15°C are obtained;

3. Taking T as the horizontal axis and k-axis as the vertical axis, for six points (T1, k ₁ ), (T2, k ₂ ), (T3, k ₃ ),

(T4, k ₄ ), (T5, k ₅ ) and (T6, k ₆ ) perform curve fitting, and use the least square method to obtain a fitting formula with T as the independent variable and k as the dependent variable,

k(T)＝a ₄ T ⁴ +a ₃ T ³ +a ₂ T ² +a ₁ T+a ₀ (1)

4. With T as the horizontal axis and n axis as the vertical axis, for six points (T1, n ₁ ), (T2, n ₂ ), (T3, n ₃ ),

(T4, n ₄ ), (T5, n ₅ ) and (T6, n ₆ ) carry out curve fitting, and use the least square method to obtain a fitting formula with T as the independent variable and n as the dependent variable,

n(T)=b ₄ T ⁴ +b ₃ T ³ +b ₂ T ² +b ₁ T+b ₀ (2)

5. The available capacity formula is:

${\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; ava</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; I</span>}}^{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; I</span>}}^{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; b</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; \&SubsetEqual;</span><span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; C</span>}}\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; C</span>}}\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; ]</span>$

(3)

6. Incorporate C _{ava, I, T} into the remaining battery power formula (4) for the power lithium-ion battery remaining in different temperature environments

The remaining power is estimated:

$\mathrm{<span\; class="notranslate">\; SOC</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; SOC</span>}}_{\mathrm{<span\; class="notranslate">\; ini</span>}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; dis</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; ava</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Among them, SOCini is the initial SOC, Cdis is the discharge capacity, and Cava is the available capacity.

The effect of this implementation mode:

In this embodiment, under different temperature conditions, for power lithium-ion batteries, discharge experiments at different rates are carried out, and the Peukert equation considering temperature is established and deduced, thereby estimating the available capacity of the battery under different temperature environments, and establishing different temperature environments. A method for estimating the remaining capacity of a power-type lithium-ion battery, thereby estimating the remaining capacity of the battery under different temperature environments. This embodiment implements the estimation of the remaining power of the power type lithium-ion battery under different temperature environments.

Specific embodiment 2: The difference between this embodiment and specific embodiment 1 is that in step 1, the lithium-ion battery is subjected to six steps of 10C, 7C, 5C, 3C, 1C and 1/3C under the temperature condition of T1=35°C. The rate discharge test is as follows:

Step 1: Charge the lithium-ion battery at a rate of 1/3C at room temperature;

Step 2: Place the lithium-ion battery in an incubator whose temperature is set to T1=35°C for 12 hours;

Step 3: Then discharge to the cut-off voltage, and record the discharge capacity of the lithium-ion battery at six rates of 10C, 7C, 5C, 3C, 1C and 1/3C, respectively denoted as C _10C1 , C _7C1 , C 5C1, C _3C1 , C _1C1 , C _{1/3C1 .} Other steps and parameters are the same as those in Embodiment 1.

Embodiment 3: The difference between this embodiment and Embodiment 1 or 2 is that in step 1, the lithium-ion battery is subjected to 10C, 7C, 5C, 3C, 1C and 1/3C under the temperature condition of T2=25°C The discharge test of six rates is as follows:

Step 1: Charge the lithium-ion battery at a rate of 1/3C at room temperature;

Step 2: Place the lithium-ion battery in an incubator whose temperature is set to T2 = 25°C for 12 hours;

Step 3: Then discharge to the cut-off voltage, and record the discharge capacity of the lithium-ion battery at six rates of 10C, 7C, 5C, 3C, 1C and 1/3C, respectively denoted as C _10C2 , C _7C 2 , C _5C2 , C _3C2 , C _1C2 , C _1/3C2 . Other step parameters are the same as those in Embodiment 1 or 2.

Specific Embodiment 4: The difference between this embodiment and one of specific embodiments 1 to 3 is that in step 1, the lithium-ion battery is subjected to 10C, 7C, 5C, 3C, 1C and 1/2 at a temperature of T3=10°C. The discharge test of the six rates of 3C is as follows:

Step 1: Charge the lithium-ion battery at a rate of 1/3C at room temperature;

Step 2: Place the lithium-ion battery in an incubator whose temperature is set to T3=10°C for 12 hours;

Step 3: Then discharge, discharge to the cut-off voltage, and record the discharge capacity of the lithium-ion battery at six rates of 10C, 7C, 5C, 3C, 1C and 1/3C, respectively denoted as C _10C3 , C _7C3 , C _5C3 , C _3C3 , C _1C3 , C _1/3C3 . Other steps and parameters are the same as in one of the specific embodiments 1 to 4.

Embodiment 5: The difference between this embodiment and one of Embodiments 1 to 4 is that in step 1, the lithium-ion battery is subjected to 10C, 7C, 5C, 3C, 1C and 1/3C under the temperature condition of T4=0°C. The discharge test of six rates is as follows:

Step 1: Charge the lithium-ion battery at a rate of 1/3C at room temperature;

Step 2: Place the lithium-ion battery in an incubator whose temperature is set to T4=0°C for 12 hours;

Step 3: Then discharge, discharge to the cut-off voltage, and record the discharge capacity of the lithium-ion battery at six rates of 10C, 7C, 5C, 3C, 1C and 1/3C, respectively denoted as C _10C4 , C _7C4 , C _5C4 , C _3C4 , C _1C4 , C _1/3C4 . Other steps and parameters are the same as one of the specific embodiments 1 to 5.

Embodiment 6: The difference between this embodiment and one of Embodiments 1 to 5 is that in step 1, the lithium-ion battery is subjected to 10C, 7C, 5C, 3C, 1C and 1/2 at a temperature of T5=-10°C. The discharge test of the six rates of 3C is as follows:

Step 1: Charge the lithium-ion battery at a rate of 1/3C at room temperature;

Step 2: Place the lithium-ion battery in an incubator whose temperature is set to T5=-10°C for 12 hours;

Step 3: Then discharge, discharge to the cut-off voltage, and record the discharge capacity of the lithium-ion battery at six rates of 10C, 7C, 5C, 3C, 1C and 1/3C, respectively denoted as C _10C5 , C _7C5 , C _5C5 , C _3C5 , C _1C5 , C _1/3C5 . Other steps and parameters are the same as one of the specific embodiments 1 to 5.

Embodiment 7: The difference between this embodiment and one of Embodiments 1 to 6 is that in step 1, the lithium-ion battery is subjected to 10C, 7C, 5C, 3C, 1C and 1C at a temperature of T6=-15°C. The discharge test of six rates of /3C is as follows:

Step 1: Charge the lithium-ion battery at a rate of 1/3C at room temperature;

Step 2: Place the lithium-ion battery in an incubator whose temperature is set to T6=-15°C for 12 hours;

Step 3: Then discharge, discharge to the cut-off voltage, and record the discharge capacity of the lithium-ion battery at six rates of 10C, 7C, 5C, 3C, 1C and 1/3C, respectively denoted as C _10C6 , C _7C6 , C _5C6 , C _3C6 , C _1C6 , C _1/3C6 . Other steps and parameters are the same as one of the specific embodiments 1 to 6.

Embodiment 8: The difference between this embodiment and one of Embodiments 1 to 7 is that in step 2, the remaining power of the power type lithium-ion battery under different temperature environments is estimated:

$\mathrm{<span\; class="notranslate">\; SOC</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; SOC</span>}}_{\mathrm{<span\; class="notranslate">\; ini</span>}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; dis</span>}}}{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; ava</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; SOC</span>}}_{\mathrm{<span\; class="notranslate">\; ini</span>}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; C</span>}}_{\mathrm{<span\; class="notranslate">\; dis</span>}}}{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; I</span>}}^{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

in,

k(T)＝a ₄ T ⁴ +a ₃ T ³ +a ₂ T ² +a ₁ T+a ₀ (6)

n(T)=b ₄ T ⁴ +b ₃ T ³ +b ₂ T ² +b ₁ T+b ₀ (7).

Other steps and parameters are the same as one of the specific embodiments 1 to 7.

Claims (8)

1. The method for estimating the residual electric quantity of the power type lithium ion battery under different temperature environments is characterized by being realized according to the following steps:

firstly, the lithium ion battery is subjected to discharge tests with six multiplying factors of 10C, 7C, 5C, 3C, 1C and 1/3C under the temperature condition that T1 is 35 ℃, so that the discharge capacities of the lithium ion battery with six multiplying factors of 10C, 7C, 5C, 3C, 1C and 1/3C are obtained and are respectively marked as C_10C1，C_7C1，C_5C1，C_3C1，C_1C1，C_1/3C1；

The lithium ion battery was subjected to discharge tests at six rates of 10C, 7C, 5C, 3C, 1C, and 1/3C under a temperature condition of T2 ═ 25 ℃, and discharge capacities at six rates of 10C, 7C, 5C, 3C, 1C, and 1/3C, respectively, denoted as C, of the lithium ion battery were obtained_10C2，C_7C2，C_5C2，C_3C2，C_1C2，C_1/3C2；

The lithium ion battery was subjected to discharge tests at six rates of 10C, 7C, 5C, 3C, 1C, and 1/3C under a temperature condition of T3 ═ 10 ℃, and discharge capacities at six rates of 10C, 7C, 5C, 3C, 1C, and 1/3C, respectively, denoted as C, of the lithium ion battery were obtained_10C3，C_7C3，C_5C3，C_3C3，C_1C3，C_1/3C3；

The lithium ion battery was subjected to discharge tests at six rates of 10C, 7C, 5C, 3C, 1C, and 1/3C under a temperature condition of T4 ═ 0 ℃, and discharge capacities at six rates of 10C, 7C, 5C, 3C, 1C, and 1/3C of the lithium ion battery were obtained, and the discharge capacities were respectively denoted as C_10C4，C_7C4，C_5C4，C_3C4，C_1C4，C_1/3C4；

The lithium ion battery was subjected to discharge tests at six rates of 10C, 7C, 5C, 3C, 1C, and 1/3C under a temperature condition of-10 ℃ at T5, and discharge capacities at six rates of 10C, 7C, 5C, 3C, 1C, and 1/3C of the lithium ion battery were obtained, and the discharge capacities were respectively denoted as C_10C5，C_7C5，C_5C5，C_3C5，C_1C5，C_1/3C5；

The lithium ion battery was subjected to discharge tests at six rates of 10C, 7C, 5C, 3C, 1C, and 1/3C at a temperature of-15 ℃ T6, and the discharge capacities at six rates of 10C, 7C, 5C, 3C, 1C, and 1/3C of the lithium ion battery were obtained, and the discharge capacities were denoted as C_10C6，C_7C6，C_5C6，C_3C6，C_1C6，C_1/3C6；

Selecting the 10C multiplying power as the highest discharge current, and selecting the 1/3C multiplying power as the lowest discharge current:

with I_10C1，I_1/3C1，C_10C1And C_1/3C1For calculation of data, the result is obtained at T1Peukert coefficients for temperature conditions of 35 ℃ k1 and n 1;

with I_10C2，I_1/3C2，C_10C2And C_1/3C2For the calculation of the data, Peukert coefficients k2 and n2 were obtained at a temperature condition of T2 ═ 25 ℃;

with I_10C3，I_1/3C3，C_10C3And C_1/3C3For the calculation of the data, Peukert coefficients k3 and n3 were obtained at a temperature condition of T3 ═ 10 ℃;

with I_10C4，I_1/3C4，C_10C4And C_1/3C4For the calculation of the data, Peukert coefficients k4 and n4 were obtained at a temperature condition of T4 ═ 0 ℃;

with I_10C5，I_1/3C5，C_10C5And C_1/3C5For the calculation of the data, the Peukert coefficients k5 and n5 were obtained at a temperature condition T5 ═ 10 ℃;

with I_10C6，I_1/3C6，C_10C6And C_1/3C6For the calculation of the data, the Peukert coefficients k6 and n6 were obtained at a temperature condition T6 ═ 15 ℃;

third, taking T as the horizontal axis and k as the vertical axis, for six points (T1, k)₁)、(T2，k₂)、(T3，k₃)、(T4，k₄)、(T5，k₅) And (T6, k)₆) Performing curve fitting, obtaining a fitting formula with T as an independent variable and k as a dependent variable by using a least square method,

k(T)＝a₄T⁴+a₃T³+a₂T²+a₁T+a₀(1)

fourthly, taking T as a horizontal axis and taking n as a vertical axis, and aiming at six points (T1, n)₁)、(T2，n₂)、(T3，n₃)、(T4，n₄)、(T5，n₅) And (T6, n)₆) Performing curve fitting, obtaining a fitting formula with T as an independent variable and n as a dependent variable by using a least square method,

n(T)＝b₄T⁴+b₃T³+b₂T²+b₁T+b₀(2)

fifthly, the available capacity formula is as follows:

<math> <mrow> <msub> <mi>C</mi> <mrow> <mi>a</mi> <mi>v</mi> <mi>a</mi> <mi>I</mi> <mo>,</mo> <mi>T</mi> </mrow> </msub> <mo>=</mo> <mi>k</mi> <mrow> <mo>(</mo> <mi>T</mi> <mo>)</mo> </mrow> <msup> <mi>I</mi> <mrow> <mo>(</mo> <mn>1</mn> <mo>-</mo> <mi>n</mi> <mo>(</mo> <mi>T</mi> <mo>)</mo> <mo>)</mo> </mrow> </msup> <mo>=</mo> <mrow> <mo>(</mo> <msub> <mi>a</mi> <mn>4</mn> </msub> <msup> <mi>T</mi> <mn>4</mn> </msup> <mo>+</mo> <msub> <mi>a</mi> <mn>3</mn> </msub> <msup> <mi>T</mi> <mn>3</mn> </msup> <mo>+</mo> <msub> <mi>a</mi> <mn>2</mn> </msub> <msup> <mi>T</mi> <mn>2</mn> </msup> <mo>+</mo> <msub> <mi>a</mi> <mn>1</mn> </msub> <mi>T</mi> <mo>+</mo> <msub> <mi>a</mi> <mn>0</mn> </msub> <mo>)</mo> </mrow> <mo>*</mo> <msup> <mi>I</mi> <mrow> <mo>(</mo> <mn>1</mn> <mo>-</mo> <mo>(</mo> <msub> <mi>b</mi> <mn>4</mn> </msub> <msup> <mi>T</mi> <mn>4</mn> </msup> <mo>+</mo> <msub> <mi>b</mi> <mn>3</mn> </msub> <msup> <mi>T</mi> <mn>3</mn> </msup> <mo>+</mo> <msub> <mi>b</mi> <mn>2</mn> </msub> <msup> <mi>T</mi> <mn>2</mn> </msup> <mo>+</mo> <msub> <mi>b</mi> <mn>1</mn> </msub> <mi>T</mi> <mo>+</mo> <msub> <mi>b</mi> <mn>0</mn> </msub> <mo>)</mo> <mo>)</mo> </mrow> </msup> <mo>,</mo> <mi>I</mi> <mo>&SubsetEqual;</mo> <mo>&lsqb;</mo> <msub> <mi>I</mi> <mrow> <mn>1</mn> <mo>/</mo> <mn>3</mn> <mi>C</mi> </mrow> </msub> <mi>A</mi> <mo>,</mo> <msub> <mi>I</mi> <mrow> <mn>10</mn> <mi>C</mi> </mrow> </msub> <mi>A</mi> <mo>&rsqb;</mo> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>3</mn> <mo>)</mo> </mrow> </mrow> </math>

sixthly, mixing C_ava,I,TAnd substituting a battery residual capacity formula (4) to estimate the residual capacity of the power type lithium ion battery under different temperature environments:

$SOC=({\mathrm{SOC}}_{ini}-\frac{C_{dis}}{C_{ava}})*100---\left(4\right)$

therein, SOC_iniIs an initial SOC, C_disIs a discharge capacity, C_avaIs the available capacity.

2. The method according to claim 1, wherein the method for estimating the remaining capacity of the power lithium ion battery under different temperature environments comprises: in the first step, the lithium ion battery is subjected to discharge tests with six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C under the temperature condition that T1 is 35 ℃, specifically:

step 1: charging the lithium ion battery at 1/3C rate under the normal temperature condition until the battery is fully charged;

step 2: setting the lithium ion battery to be placed in a constant temperature box with the temperature T1 being 35 ℃ for 12 hours;

and step 3: then, discharging is carried out until the discharge reaches a cut-off voltage, and the discharge capacities of the lithium ion battery at six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C are recorded respectively and are respectively marked as C_10C1，C_7C1，C_5C1，C_3C1，C_1C1，C_1/3C1。

3. The method according to claim 1, wherein the method for estimating the remaining capacity of the power lithium ion battery under different temperature environments comprises: in the first step, the lithium ion battery is subjected to discharge tests with six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C under the temperature condition that T2 is 25 ℃, specifically:

step 1: charging the lithium ion battery at 1/3C rate under the normal temperature condition until the battery is fully charged;

step 2: setting the lithium ion battery to be placed in a constant temperature box with the temperature T2 being 25 ℃ for 12 hours;

and step 3: then, discharging is carried out until the discharge reaches a cut-off voltage, and the discharge capacities of the lithium ion battery at six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C are recorded respectively and are respectively marked as C_10C2，C_7C2，C_5C2，C_3C2，C_1C2，C_1/3C2。

4. The method according to claim 1, wherein the method for estimating the remaining capacity of the power lithium ion battery under different temperature environments comprises: in the first step, the lithium ion battery is subjected to discharge tests with six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C under the temperature condition that T3 is 10 ℃, specifically:

step 1: charging the lithium ion battery at 1/3C rate under the normal temperature condition until the battery is fully charged;

step 2: setting the lithium ion battery to be placed in a constant temperature box with the temperature T3 being 10 ℃ for 12 hours;

and step 3: then, discharging is carried out until the discharge reaches a cut-off voltage, and the discharge capacities of the lithium ion battery at six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C are recorded respectively and are respectively marked as C_10C3，C_7C3，C_5C3，C_3C3，C_1C3，C_1/3C3。

5. The method according to claim 1, wherein the method for estimating the remaining capacity of the power lithium ion battery under different temperature environments comprises: in the first step, the lithium ion battery is subjected to discharge tests with six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C under the temperature condition that T4 is 0 ℃, specifically:

step 1: charging the lithium ion battery at 1/3C rate under the normal temperature condition until the battery is fully charged;

step 2: placing the lithium ion battery in a constant temperature box with the temperature T4 being 0 ℃ for 12 hours;

and step 3: then, discharging is carried out until the discharge reaches a cut-off voltage, and the discharge capacities of the lithium ion battery at six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C are recorded respectively and are respectively marked as C_10C4，C_7C4，C_5C4，C_3C4，C_1C4，C_1/3C4。

6. The method according to claim 1, wherein the method for estimating the remaining capacity of the power lithium ion battery under different temperature environments comprises: in the first step, the lithium ion battery is subjected to discharge tests with six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C under the temperature condition that T5 is-10 ℃, specifically:

step 1: charging the lithium ion battery at 1/3C rate under the normal temperature condition until the battery is fully charged;

step 2: setting the temperature of the lithium ion battery to be in a constant temperature box with T5-10 ℃ for 12 hours;

and step 3: then discharging to cut-off voltage, andrecording the discharge capacities of the lithium ion battery at six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C respectively, and recording the discharge capacities as C_10C5，C_7C5，C_5C5，C_3C5，C_1C5，C_1/3C5。

7. The method according to claim 1, wherein the method for estimating the remaining capacity of the power lithium ion battery under different temperature environments comprises: in the first step, the lithium ion battery is subjected to discharge tests with six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C under the temperature condition that T6 is-15 ℃, specifically:

step 1: charging the lithium ion battery at 1/3C rate under the normal temperature condition until the battery is fully charged;

step 2: setting the temperature of the lithium ion battery to be in a constant temperature box with T6-15 ℃ for 12 hours;

and step 3: then, discharging is carried out until the discharge reaches a cut-off voltage, and the discharge capacities of the lithium ion battery at six multiplying powers of 10C, 7C, 5C, 3C, 1C and 1/3C are recorded respectively and are respectively marked as C_10C6，C_7C6，C_5C6，C_3C6，C_1C6，C_1/3C6。

8. The method according to claim 1, wherein the method for estimating the remaining capacity of the power lithium ion battery under different temperature environments comprises: estimating the residual electric quantity of the power type lithium ion battery under different temperature environments:

$SOC=({\mathrm{SOC}}_{ini}-\frac{C_{dis}}{C_{ava,I,T}})*100=({\mathrm{SOC}}_{ini}-\frac{C_{dis}}{k\left(T\right)I^{(1-n(T\left)\right)}})*100---\left(5\right).$