A secondary battery that generates or includes metal-ion contaminants selected from copper ions, manganese ions, nickel ions, cobalt ions, iron ions, aluminum ions, chrome ions, molybdenum ions, tin ions or combinations thereof, the battery comprising: an anode; a cathode; a coated or uncoated battery separator between the anode and the cathode, wherein the coated or uncoated battery separator comprises a trap layer; and an electrolyte. The battery improve yield rate of initial charge and aging process and exhibits prolonged useful life due to the separator, which reduces or eliminates metal-ion contamination in the battery.

A positive electrode material includes a first lithium manganese iron phosphate material in an aggregate form, a second and third lithium manganese iron phosphate materials in an aggregate and/or single-crystal-like form, and a fourth and fifth lithium manganese iron phosphate materials in a single-crystal-like form. D.sub.50.sup.5<D.sub.50.sup.4<D.sub.50.sup.3<D.sub.50.sup.2<D.sub.50.sup.1, D.sub.50.sup.2=aD.sub.50.sup.1, D.sub.50.sup.3=bD.sub.50.sup.1, D.sub.50.sup.4=cD.sub.50.sup.1, D.sub.50.sup.5=dD.sub.50.sup.1, and 5 μm≤D.sub.50.sup.1≤15 μm. 0.35≤a≤0.5, 0.2≤b≤0.27, 0.17≤c≤0.18, and 0.15≤d≤0.16. Molar ratios of manganese to iron in the first, the second, the third and the fourth lithium manganese iron phosphate materials increase sequentially, and a molar ratio of manganese to iron in the fifth lithium manganese iron phosphate material is greater than that in the third lithium manganese iron phosphate material.

A positive electrode material includes a first lithium manganese iron phosphate material in an aggregate form, a second and third lithium manganese iron phosphate materials in an aggregate and/or single-crystal-like form, and a fourth and fifth lithium manganese iron phosphate materials in a single-crystal-like form. D.sub.50.sup.5<D.sub.50.sup.4<D.sub.50.sup.3<D.sub.50.sup.2<D.sub.50.sup.1, D.sub.50.sup.2=aD.sub.50.sup.1, D.sub.50.sup.3=bD.sub.50.sup.1, D.sub.50.sup.4=cD.sub.50.sup.1, D.sub.50.sup.5=dD.sub.50.sup.1, and 5 μm≤D.sub.50.sup.1≤15 μm. 0.35≤a≤0.5, 0.2≤b≤0.27, 0.17≤c≤0.18, and 0.15≤d≤0.16. Molar ratios of manganese to iron in the first, the second, the third and the fourth lithium manganese iron phosphate materials increase sequentially, and a molar ratio of manganese to iron in the fifth lithium manganese iron phosphate material is greater than that in the third lithium manganese iron phosphate material.

A positive electrode according to the present invention is a positive electrode of a lithium ion secondary battery in which a coating film containing a positive electrode active material is pressed against a surface of a positive electrode base material, and the positive electrode active material is a mixture of a first active material containing single particles of lithium composite oxide and a second active material containing secondary particles which are aggregated single particles of lithium composite oxide.

A positive electrode according to the present invention is a positive electrode of a lithium ion secondary battery in which a coating film containing a positive electrode active material is pressed against a surface of a positive electrode base material, and the positive electrode active material is a mixture of a first active material containing single particles of lithium composite oxide and a second active material containing secondary particles which are aggregated single particles of lithium composite oxide.

A negative electrode for a lithium secondary battery, a lithium secondary battery including the negative electrode, and a method for manufacturing the lithium secondary battery, where the negative electrode includes a negative electrode current collector; and a negative electrode active material layer on at least one surface of the negative electrode current collector. The negative electrode active material layer includes a Si-containing negative electrode active material, a conductive material and a first binder polymer. The Si-containing negative electrode active material has cracks formed after activation, and a second binder polymer is present in the cracks. The first binder polymer and the second binder polymer are heterogeneous (e.g., different from each other). The lithium secondary battery shows improved life characteristics.

According to one embodiment, provided is an electrode including an active material that includes a titanium-containing oxide. The active material has an average primary particle size of 200 nm or more and 600 nm or less. A specific surface area S.sub.A according to a nitrogen adsorption method and a pore specific surface area S.sub.B according to mercury porosimetry of the electrode satisfy a relationship of 0.3≤S.sub.A/S.sub.B<0.6.

According to one embodiment, provided is an electrode including an active material that includes a titanium-containing oxide. The active material has an average primary particle size of 200 nm or more and 600 nm or less. A specific surface area S.sub.A according to a nitrogen adsorption method and a pore specific surface area S.sub.B according to mercury porosimetry of the electrode satisfy a relationship of 0.3≤S.sub.A/S.sub.B<0.6.

A positive electrode (100) includes a positive electrode current collector (110), a positive electrode mixture (120), and a mixture (130). The positive electrode current collector (110) has a first surface (112). The first surface (112) of the positive electrode current collector (110) includes a first region (112a), a second region (112b), and a third region (112c). The positive electrode (100) satisfies the following expression (1).

0≤L3/(L1+L3)≤0.075  (1)

Here, L1 is a length of the positive electrode (100) of the first region (112a) of the positive electrode (100) in one direction (first direction (X)), and L3 is a length of the third region (112c) of the positive electrode (100) in the one direction (first direction (X)).

An electrode for an all-solid-state battery includes a current collector, a carbon material layer having an adhesive property, and an active material layer in this order in the thickness direction, and the carbon material layer contains a carbon material, a dispersion material, and a binder.