Anode and secondary battery

Abstract

A battery capable of improving cycle characteristics is provided. An anode includes: an anode current collector, and an anode active material layer arranged on the anode current collector, in which the anode active material layer includes an anode active material including silicon (Si), and including a pore group with a diameter ranging from 3 nm to 50 nm both inclusive, and the volumetric capacity per unit weight of silicon of the pore group with a diameter ranging from 3 nm to 50 nm both inclusive is 0.2 cm 3 /g or less, the volumetric capacity being measured by mercury porosimetry using a mercury porosimeter.

1 . An anode comprising:
 an anode current collector; and   an anode active material layer arranged on the anode current collector,   wherein the anode active material layer includes an anode active material including silicon (Si), and including a pore group with a diameter ranging from 3 nm to 50 nm both inclusive, and   the volumetric capacity per unit weight of silicon of the pore group with a diameter ranging from 3 nm to 50 nm both inclusive is 0.2 cm 3 /g or less, the volumetric capacity being measured by mercury porosimetry using a mercury porosimeter.   
   
   
       2 . The anode according to  claim 1 , wherein
 the volumetric capacity per unit weight of silicon of the pore group with a diameter ranging from 3 nm to 50 nm both inclusive is 0.05 cm 3 /g or less.   
   
   
       3 . The anode according to  claim 1 , wherein
 the volumetric capacity per unit weight of silicon of the pore group with a diameter ranging from 3 nm to 50 nm both inclusive is 0 cm 3 /g.   
   
   
       4 . The anode according to  claim 1 , wherein
 the volumetric capacity per unit weight of silicon of a pore group with a diameter ranging from 3 nm to 20 nm both inclusive is 0.2 cm 3 /g or less, the volumetric capacity being measured by mercury porosimetry using a mercury porosimeter.   
   
   
       5 . The anode according to  claim 4 , wherein
 the volumetric capacity per unit weight of silicon of the pore group with a diameter ranging from 3 nm to 20 nm both inclusive is 0.05 cm 3 /g or less.   
   
   
       6 . The anode according to  claim 4 , wherein
 the volumetric capacity per unit weight of silicon of the pore group with a diameter ranging from 3 nm to 20 nm both inclusive is 0 cm 3 /g.   
   
   
       7 . The anode according to  claim 1 , wherein
 the anode active material layer includes an oxide-containing film in pores.   
   
   
       8 . The anode according to  claim 7 , wherein
 the oxide-containing film includes at least one kind of oxide selected from the group consisting of an oxide of silicon, an oxide of germanium (Ge) and an oxide of tin (Sn).   
   
   
       9 . The anode according to  claim 7 , wherein
 the oxide-containing film is formed by a liquid-phase deposition method, a sol-gel method, a coating method or a dip coating method.   
   
   
       10 . The anode according to  claim 1 , wherein
 the anode active material layer includes a metal material which is not alloyed with an electrode reactant in pores.   
   
   
       11 . The anode according to  claim 10 , wherein
 the metal material includes at least one kind selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn) and copper (Cu).   
   
   
       12 . The anode according to  claim 10 , wherein
 the metal material is formed by an electrolytic plating method or an electroless plating method.   
   
   
       13 . The anode according to  claim 1 , wherein
 the anode active material is in the form of a plurality of particles.   
   
   
       14 . The anode according to  claim 13 , wherein
 the anode active material has a multilayer configuration in its particles.   
   
   
       15 . The anode according to  claim 1 , wherein
 the anode active material is formed by a vapor-phase method.   
   
   
       16 . The anode according to  claim 1 , wherein
 the anode active material includes oxygen (O), and the oxygen content in the anode active material is within a range from 3 at % to 40 at % both inclusive.   
   
   
       17 . The anode according to  claim 1 , wherein
 the anode active material includes at least one kind of metal element selected from the group consisting of iron, cobalt, nickel, chromium (Cr), titanium (Ti) and molybdenum (Mo).   
   
   
       18 . The anode according to  claim 1 , wherein
 the anode active material includes an oxygen-containing region including oxygen in its thickness direction, and the oxygen content in the oxygen-containing region is higher than the oxygen content in a region other than the oxygen-containing region.   
   
   
       19 . The anode according to  claim 1 , wherein
 the ten-point height of roughness profile Rz of the surface of the anode current collector is within a range from 1.5 μm to 6.5 μm both inclusive.   
   
   
       20 . A secondary battery comprising a cathode, an anode and an electrolytic solution, wherein
 the anode includes an anode current collector and an anode active material layer arranged on the anode current collector,   the anode active material layer includes an anode active material including silicon, and including a pore group with a diameter ranging from 3 nm to 50 nm both inclusive, and   the volumetric capacity per unit weight of silicon of the pore group with a diameter ranging from 3 nm to 50 nm both inclusive is 0.2 cm 3 /g or less, the volumetric capacity being measured by mercury porosimetry using a mercury porosimeter.   
   
   
       21 . The secondary battery according to  claim 20 , wherein
 the volumetric capacity per unit weight of silicon of the pore group with a diameter ranging from 3 nm to 50 nm both inclusive is 0.05 cm 3 /g or less.   
   
   
       22 . The secondary battery according to  claim 20 , wherein
 the volumetric capacity per unit weight of silicon of the pore group with a diameter ranging from 3 nm to 50 nm both inclusive is 0 cm 3 /g.   
   
   
       23 . The secondary battery according to  claim 20 , wherein
 the volumetric capacity per unit weight of silicon of a pore group with a diameter ranging from 3 nm to 20 nm both inclusive is 0.2 cm 3 /g or less, the volumetric capacity being measured by mercury porosimetry using a mercury porosimeter.   
   
   
       24 . The secondary battery according to  claim 23 , wherein
 the volumetric capacity per unit weight of silicon of the pore group with a diameter ranging from 3 nm to 20 nm both inclusive is 0.05 cm 3 /g or less.   
   
   
       25 . The secondary battery according to  claim 23 , wherein
 the volumetric capacity per unit weight of silicon of the pore group with a diameter ranging from 3 nm to 20 nm both inclusive is 0 cm 3 /g.   
   
   
       26 . The secondary battery according to  claim 20 , wherein
 the anode active material layer includes an oxide-containing film in pores.   
   
   
       27 . The secondary battery according to  claim 26 , wherein
 the oxide-containing film includes at least one kind of oxide selected from the group consisting of an oxide of silicon, an oxide of germanium and an oxide of tin.   
   
   
       28 . The secondary battery according to  claim 26 , wherein
 the oxide-containing film is formed by a liquid-phase deposition method, a sol-gel method, a coating method or a dip coating method.   
   
   
       29 . The secondary battery according to  claim 20 , wherein
 the anode active material layer includes a metal material which is not alloyed with an electrode reactant in pores.   
   
   
       30 . The secondary battery according to  claim 29 , wherein
 the metal material includes at least one kind selected from the group consisting of iron, cobalt, nickel, zinc and copper.   
   
   
       31 . The secondary battery according to  claim 29 , wherein
 the metal material is formed by an electrolytic plating method or an electroless plating method.   
   
   
       32 . The secondary battery according to  claim 20 , wherein
 the anode active material is in the form of a plurality of particles.   
   
   
       33 . The secondary battery according to  claim 32 , wherein
 the anode active material has a multilayer configuration in its particles.   
   
   
       34 . The secondary battery according to  claim 20 , wherein
 the anode active material is formed by a vapor-phase method.   
   
   
       35 . The secondary battery according to  claim 20 , wherein
 the anode active material includes oxygen, and the oxygen content in the anode active material is within a range from 3 at % to 40 at % both inclusive.   
   
   
       36 . The secondary battery according to  claim 20 , wherein
 the anode active material includes at least one kind of metal element selected from the group consisting of iron, cobalt, nickel, chromium, titanium and molybdenum.   
   
   
       37 . The secondary battery according to  claim 20 , wherein
 the anode active material includes an oxygen-containing region including oxygen in its thickness direction, and the oxygen content in the oxygen-containing region is higher than the oxygen content in a region other than the oxygen-containing region.   
   
   
       38 . The secondary battery according to  claim 20 , wherein
 the ten-point height of roughness profile Rz of the surface of the anode current collector is within a range from 1.5 μm to 6.5 μm both inclusive.   
   
   
       39 . The secondary battery according to  claim 20 , wherein
 the electrolytic solution includes a solvent including a sultone.   
   
   
       40 . The secondary battery according to  claim 39 , wherein
 the sultone is 1,3-propene sultone.   
   
   
       41 . The secondary battery according to  claim 20 , wherein
 the electrolytic solution includes a solvent including a cyclic carbonate including an unsaturated bond.   
   
   
       42 . The secondary battery according to  claim 41 , wherein
 the cyclic carbonate including an unsaturated bond is vinylene carbonate or vinyl ethylene carbonate.   
   
   
       43 . The secondary battery according to  claim 20 , wherein
 the electrolytic solution includes a solvent including a fluorinated carbonate.   
   
   
       44 . The secondary battery according to  claim 43 , wherein
 the fluorinated carbonate is difluoroethylene carbonate.   
   
   
       45 . The secondary battery according to  claim 20 , wherein
 the electrolytic solution includes an electrolyte salt including boron (B) and fluorine (F).   
   
   
       46 . The secondary battery according to  claim 45 ,
 the electrolyte salt is lithium tetrafluoroborate (LiBF 4 ).   
   
   
       47 . The secondary battery according to  claim 20 , wherein
 the cathode, the anode and the electrolytic solution are contained in a cylindrical or prismatic package member.   
   
   
       48 . The secondary battery according to  claim 47 , wherein
 the package member includes iron or an iron alloy.