POSITIVE ELECTRODE ACTIVE MATERIAL, POSITIVE ELECTRODE USING THE SAME AND NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY
A positive electrode active material includes: a particle containing a positive electrode material capable of intercalating and deintercalating an electrode reactant; and a film provided in at least a part of the particle and having a peak of C 2 H 5 S + , C 3 H 7 S + or C 4 H 9 S + obtained by cation analysis by time of flight secondary ion mass spectrometry.
1 . A non-aqueous electrolyte secondary battery comprising:
a positive electrode having a positive electrode active material;
a negative electrode;
a separator; and
an electrolyte, wherein
the positive electrode active material includes
a particle containing a positive electrode material capable of intercalating and deintercalating an electrode reactant; and
a film provided in at least a part of the particle wherein
a film having a peak of C 2 H 5 S + , C 3 H 7 S + or C 4 H 9 S + obtained by cation analysis by time of flight secondary ion mass spectrometry, and wherein
an upper limit discharge voltage is 4.35 V or more and not more than 4.80 V.
2 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein the particle includes at least lithium and one or more transition metal elements.
3 . The non-aqueous electrolyte secondary battery according to claim 2 , wherein the particle includes cobalt (Co) as a principal transition metal element and has a layered structure.
4 . The non-aqueous electrolyte secondary battery according to claim 3 , wherein one or more elements different from the principal transition metal element care included in at least a part of the surface of the particle.
5 . The non-aqueous electrolyte secondary battery according to claim 4 , wherein the one or more elements include at least one of nickel (Ni), manganese (Mn) and phosphorus (P).
6 . The non-aqueous electrolyte secondary battery according to claim 4 , wherein the one or more elements include manganese (Mn) and any one of nickel (Ni) and phosphorus (P).
7 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein a lower limit discharge voltage is 2.00 V or more and not more than 3.30 V.
8 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein an average particle size of the positive electrode active material is 2.0 μm or more and not more than 50 μm.
9 . A method for preparing a non-aqueous electrolyte secondary battery including a positive electrode having a positive electrode active material, a negative electrode, a separator, and an electrolyte, the positive electrode active material including a particle containing a positive electrode material capable of intercalating and deintercalating an electrode reactant, at least a part of the particle being provided with a film having a peak of C 2 H 5 S + , C 3 H 7 S + or C 4 H 9 S + obtained by cation analysis by time of flight secondary ion mass spectrometry, the method comprising:
forming the film on at least a part of the particle by using the compound expressed by the formula (1)
wherein R1 and R2 each represents a hydrogen group or a hydrocarbon group, provided that R1 and R2 may be bonded to each other to form a cyclic structure; and a1 and b1 each represents an integer of 1 or more.
10 . The method according to claim 9 , wherein the particle includes at least lithium and one or more transition metal elements.
11 . The method according to claim 10 , wherein the particle contains cobalt (Co) as a principal transition metal element and has a layered structure.
12 . The method according to claim 11 , wherein one or more elements different from the principal transition metal element are included in at least a part of the surface of the particle.
13 . The method according to claim 12 , wherein the one or more elements include at least one of nickel (Ni), manganese (Mn) and phosphorus (P).
14 . The method according to claim 12 , wherein the one or more elements include manganese (Mn) and any one of nickel (Ni) and phosphorus (P).
15 . The method according to claim 9 , wherein a lower limit discharge voltage is 2.00 V or more and not more than 3.30 V.
16 . The method according to claim 9 , wherein an average particle size of the positive electrode active material is 2.0 μm or more and not more than 50 μm.