A sacrificial positive active material for a lithium-ion electrochemical element which is a compound of formula (Li.sub.2O).sub.x (MnO.sub.2).sub.y(MnO).sub.z(MO.sub.a).sub.t in which: x+y+z+t=1; 1−x−y≥0; 0.97≥x≥0.6; y≤0.45; x −0.17; y≥0; y+z>0; t≥0; 1≤a<3. M is selected from the group consisting of Fe, Co, Ni, B, Al, Ti, Si, V, Mo, Zr and a mixture thereof.

This application describes a process for the preparation of carbon-coated particles, where the particles comprise an electrochemically active material. The process comprises the steps of emulsion polymerization, drying and thermally treating the polymer to obtain a nano-layer of carbon on the particles, where the carbon layer comprises fibers and nitrogen-containing polyaromatics have a graphene-like structure. The application also further relates to the particles produced by the method as well as to electrode materials, electrodes and electrochemical cells comprising the particles.

A positive electrode slurry composition of the present application may comprise a positive electrode active material, a lithium-supplementing agent and a binder, wherein the positive electrode active material may include a lithium-containing phosphate represented by formula (I),

LiFe.sub.1-b1-c1Mn.sub.b1M.sup.1.sub.c1PO.sub.4   formula (I) in which 0≤b1≤1, 0≤c1≤0.1, and M.sup.1 is selected from at least one of transition metal elements and non-transition metal elements in addition to Fe and Mn; the lithium-supplementing agent may be selected from one or more of lithium metal oxides of Li.sub.a1M.sup.2O.sub.0.5(2+a1), Li.sub.2M.sup.3O.sub.3, Li.sub.2M.sup.4O.sub.4, Li.sub.3M.sup.5O.sub.4, Li.sub.5M.sup.6O.sub.4, and Li.sub.5M.sup.7O.sub.6, and the binder may be represented by formula (II):

##STR00001## in which R.sub.1 and R.sub.2 are independently H or F, x, y, and z are all positive integers, and 0.52≤(4x+3y+2z)/(4x+4y+4z)≤0.7.

According to one embodiment, an electrode includes a current collector and an active material layer. The active material layer is disposed on at least one of faces of the current collector. The active material layer comprises active materials which include at least a cobalt-containing oxide and a lithium nickel manganese oxide. A ratio of a weight of the cobalt-containing oxide to a total of weights of the cobalt-containing oxide and the lithium nickel manganese oxide is 5 wt % or more and 40 wt % or less.

An all-solid battery includes a multilayer structure that includes pairs of positive electrode layers and pairs of negative electrode layers, first solid electrolyte layers, second solid electrolyte layers, and third solid electrolyte layers, the pairs of positive electrode layers and the pairs of negative electrode layers being alternately stacked, each of the first solid electrolyte layers being interposed between each of the pairs of positive electrode layers, each of the second solid electrolyte layers being interposed between each of the pairs of negative electrode layers, each of the third solid electrolyte layers being interposed between the positive electrode layer and the negative electrode layer, wherein a thickness of the third solid electrolyte layer is different from at least one of a thickness of the first electrolyte layer and a thickness of the second electrolyte layer.

A use, in an electrolyte for a battery, of an additive which includes at least one organocatalyst. Also, a method of preventing the contact between the anode and residual water in a battery and/or reducing the level of gas in a battery. Moreover, an electrolyte for a battery, including an additive which includes at least one organocatalyst. Moreover, a battery including an electrolyte which includes an additive which comprises at least one organocatalyst.

A lithium ion battery includes a cathode, which has a composite cathode active material, and an anode, which has an anode active material. The composite cathode active material includes at least a first and a second cathode active material, wherein the second cathode active material is a compound having an olivine structure, and wherein at least a lithiation degree of the first cathode active material differs from a lithiation degree of the second cathode active material. Prior to electrolyte filling or the first discharging and/or charging process of the lithium ion battery, the lithiation degree of the first cathode active material is higher than the lithiation degree of the second cathode active material. Prior to electrolyte filling or the first discharging and/or charging process of the lithium ion battery, the anode active material is pre-lithiated. A method for producing a lithium ion battery of this kind is also described.

Manufacturing a lithium-ion battery includes assembling the lithium-ion battery; and performing an initial charging on the lithium-ion battery. The lithium-ion battery includes a positive electrode, a negative electrode, and an electrolyte; the negative electrode contains a negative electrode active material containing a precursor of a silicon material, the precursor having a composition represented by SiO.sub.x where a relationship of 0<x<2 is satisfied. The initial charging includes a first step where the charging is performed to an intermediate voltage at a first current rate, and a second step where the charging is performed from the intermediate voltage to a maximum voltage at a second current rate. The first current rate is lower than 0.5 C; the second current rate is higher than the first current rate; and the intermediate voltage is 3.75 V or higher.

A method for making a material of formula Li.sub.xM.sub.1-zD.sub.zPO.sub.4, where M is one or more transition metals, D represents one or more elements selected from the group consisting of Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Sc, Y, and rare earth elements, 0.8≤x≤1.2 and 0≤z≤0.2, the method comprising the steps of: a) forming a mixture comprising a source of the one or more transition metals, a source of phosphorus, a source of lithium and a surfactant, and optionally a source of D, wherein (i) a ratio of Li:PO.sub.4:(M+D) relative to the stoichiometry required to form the material is within the range of 1.04-1.10:1.00-1.05:1, or (ii) a ratio of (Li+PO.sub.4):(M+D) relative to the stoichiometry required to form the material is greater than 2.05; b) drying the mixture from step (a) to form particles r a powder; and c) thermally treating the particles or powder from step (b) to form the material.

This application provides a secondary battery and a preparation method thereof, and a battery module, battery pack, and apparatus containing a secondary battery. The secondary battery includes a positive electrode plate, the positive electrode plate includes a positive electrode current collector and a positive electrode film layer that is disposed on the positive electrode current collector and that includes a positive electrode active material, where the positive electrode active material includes a first material and a second material, the first material contains lithium transition metal oxide, the second material contains lithium transition metal phosphate, the lithium transition metal phosphate includes secondary particles formed by agglomeration of primary particles, and the second material has a lower discharge platform voltage than the first material with respect to a same type of counter electrode.