POROUS MATERIAL AND PREPARATION METHOD THEREOF, CURRENT COLLECTOR, SECONDARY BATTERY, AND APPARATUS

1 . A porous material, characterized in that the porous material has pores of a first pore size and pores of a second pore size, wherein

the first pore size is n micrometers, and 0.5≤n≤20;

the second pore size is m nanometers, and 10<m<400; and

an apparent volume of the porous material is V, a total pore volume of the pores of the first pore size is V 1 , a total pore volume of the pores of the second pore size is V 2 , and the porous material satisfies the following relationships:

(

V

1

+

V

2

)

/

V

=

20

⁢

%

-

90

⁢

%

;

V

2

/

V

=

15

⁢

%

-

70

⁢

%

;

and

V

1

/

V

=

5

⁢

%

-

70

⁢

%

.

2 . The porous material according to claim 1 , characterized in that a total specific surface area of the porous material is S, a specific surface area of the pores of the first pore size is S 1 , and a specific surface area of the pores of the second pore size is S 2 ;

wherein

⁢

S

1

/

S

=

7

⁢

%

-

32

⁢

%

;

and

S

2

/

S

=

68

⁢

%

-

93

⁢

%

.

3 . The porous material according to claim 1 , wherein the porous material has one or more of the following characteristics:

(1) the second pore size is m nanometers, and 20<m<200; and

(2) the first pore size is n micrometers, and 0.5≤n≤10.

4 . The porous material according to claim 1 , wherein the porous material is made of a metal substance or an alloy containing element M, and the element M is selected from copper, aluminum, or a combination thereof.

5 . A porous material preparation method, comprising:

providing a multiphase alloy, wherein the multiphase alloy contains an αMn phase and a γMn-M phase, and element M is selected from copper, aluminum, or a combination thereof; and

removing at least part of element Mn from the αMn phase and at least part of element Mn from the γMn-M phase by using a dealloying method; wherein

the porous material has pores of a first pore size and pores of a second pore size;

the first pore size is n micrometers, and 0.5≤n≤20;

the second pore size is m nanometers, and 10<m<400; and

an apparent volume of the porous material is V, a total pore volume of the pores of the first pore size is V 1 , a total pore volume of the pores of the second pore size is V 2 , and the porous material satisfies the following relationships:

(

V

1

+

V

2

)

/

V

=

20

⁢

%

-

90

⁢

%

;

V

2

/

V

=

15

⁢

%

-

70

⁢

%

;

and

V

1

/

V

=

5

⁢

%

-

70

⁢

%

.

6 . The method according to claim 5 , characterized by one or more of the following:

(1) based on all element Mn in the αMn phase, at least more than 90 at. % of element Mn is removed from the αMn phase using the dealloying method;

(2) based on all element Mn in the γMn-M phase, at least more than 90 at. % of element Mn is removed from the γMn-M phase using the dealloying method; and

(3) based on all the element M in the multiphase alloy, less than 10 at. % of the element M is removed using the dealloying method.

7 . The method according to claim 5 , characterized by one or more of the following:

(1) a percentage of element Mn in the αMn phase is >99 at. %; and

(2) a percentage of element Mn in the γMn-M phase is 40 at. %−80 at. %.

8 . The method according to claim 5 , wherein the γMn-M phase is a solid solution.

9 . The method according to claim 5 , characterized by one or more of the following:

(1) a percentage of the αMn phase in the multiphase alloy is 22 vol %−70 vol %; and

(2) a percentage of the γMn-M phase in the multiphase alloy is 30 vol %−78 vol %.

10 . The method according to claim 5 , characterized by one or more of the following:

(1) in a metallographic image of the multiphase alloy, an average size of the αMn phase is 0.5-10 micrometers; and

(2) in the metallographic image of the multiphase alloy, an average size of the γMn-M phase is 0.5-5 micrometers.

11 . The method according to claim 5 , wherein the αMn phase and the γMn-M phase are uniformly distributed in the multiphase alloy.

12 . The method according to claim 5 , wherein the multiphase alloy contains element Mn and the element M, a percentage of element Mn is 60 at. %−90 at. %, and a percentage of the element M is 10 at. %−40 at. % and the element M is selected from copper, aluminum, or a combination thereof.

13 . The method according to claim 5 , wherein the dealloying method is selected from chemical corrosion, electrochemical corrosion, or a combination thereof.

14 . The method according to claim 5 , further comprising steps of preparing the multiphase alloy, wherein the steps specifically comprise:

providing an alloy precursor, wherein the alloy precursor contains the element M and element Mn, and the element M is selected from copper, aluminum, or a combination thereof;

performing first heat treatment on the alloy precursor to obtain a first product, wherein the first product contains a γMn-M phase; and

performing second heat treatment on the product obtained in the previous step to obtain a second product, wherein the second product contains an αMn phase and a γMn-M phase.

15 . The method according to claim 14 , wherein the method has one or more of the following characteristics:

(1) a temperature for the first heat treatment is 700° C.-865° C.;

(2) a time for the first heat treatment is 0.16 hours or longer;

(3) cooling is performed at a cooling speed of 20° C./s−1000° C./s after the first heat treatment;

(4) a percentage of the γMn-M phase in the first product is 95 vol %−100 vol %; and

(5) the method further comprises an operation of plasticizing the first product prior to the second heat treatment.

16 . The method according to claim 14 , wherein the method has one or more of the following characteristics:

(1) a temperature for the second heat treatment is 500° C.-700° C.;

(2) a time for the second heat treatment is 1 hour-4 hours;

(3) cooling is performed at a cooling speed of 20° C./s−1000° C./s after the second heat treatment; and

(4) a percentage of the αMn phase in the second product is 22 vol %-70 vol % and a percentage of the γMn-M phase is 30 vol %−78 vol %.

17 . The method according to claim 5 , wherein the alloy precursor is an ingot.

18 . The method according to claim 5 , wherein a total specific surface area of the porous material obtained using the method is S, a specific surface area of the pores of the first pore size is S 1 , and a specific surface area of the pores of the second pore size is S 2 ;

wherein

⁢

S

1

/

S

=

7

⁢

%

-

32

⁢

%

;

and

S

2

/

S

=

68

⁢

%

-

93

⁢

%

.

19 . A porous material, wherein the porous material is prepared using the method according to claim 5 .

20 . A current collector, comprising the porous material according to claim 1 .

21 . A secondary battery, comprising the current collector according to claim 20 ; wherein

optionally, the secondary battery is an anode-free metal battery; or

optionally, a negative electrode active material of the secondary battery contains metal or alloy.

22 . An apparatus, comprising the secondary battery according to claim 21 , wherein the secondary battery provides electric energy for the apparatus.