A lithium secondary battery includes a positive electrode, a negative electrode, a lithium ion conductive nonaqueous electrolyte, and a separator disposed between the positive electrode and the negative electrode. On the negative electrode, lithium metal deposits during charging, and the lithium metal is dissolved during discharging; the negative electrode includes a negative electrode current collector, and a plurality of layers stacked on the negative electrode current collector; the plurality of layers include a first layer, a second layer, and a third layer; of the first to third layers, the first layer is closest to the negative electrode current collector, and the third layer is farthest from the negative electrode current collector; the first layer contains a material capable of storing lithium ions; the second layer contains lithium metal, and the third layer has an insulation property and a lithium ion permeability.

The present application relates to a battery module including a first-type battery cell and a second-type battery cell at least connected in series, where the first-type battery cell and the second-type battery cell are battery cells of different chemical systems, the first-type battery cell includes N first battery cell(s), and the second-type battery cell includes M second battery cell(s), where N and M are positive integers; and when a battery state of health (SOH) of a first battery cell is the same as an SOH of a second battery cell, and a state of charge (SOC) of the first battery cell is the same as an SOC of the second battery cell, a ratio of a total charge capacity of a first negative electrode sheet of the first battery cell to a total charge capacity of a second negative electrode sheet of the second battery cell is 0.8 to 1.2.

According to one embodiment, provided is a nonaqueous electrolyte battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte. The positive electrode includes lithium manganese composite oxide particles having a spinel crystal structure and lithium cobalt composite oxide particles. The negative electrode includes a titanium-containing oxide. The nonaqueous electrolyte contains a propionate ester. The battery satisfies 0.8≤p/n≤1.2 and 1≤w/s≤60. p denotes a capacity per unit area of the positive electrode. n denotes a capacity per unit area of the negative electrode. w denotes a content of the propionate ester in the nonaqueous electrolyte and is in a range of 10% by weight to 60% by weight. s denotes an average particle size of the lithium manganese composite oxide particles.

Pre-lithiation methods using lithium vanadium fluorophosphate (e.g., LiVPO.sub.4F and its derivatives) (“LVPF”) as a cathode active material in a lithium-ion secondary battery. The pre-lithiation methods include compensating for an expected loss of active lithium by selecting LVPF having a specific pre-lithiated chemistry (or a blend of LVPF selected to have a specific pre-lithiated chemistry) and selecting a total amount of the pre-lithiated LVPF. The pre-lithiation methods may include initially charging the lithium-ion secondary battery at the lower of the two charge/discharge plateaus of LVPF to release active lithium.

This charging method is A method for charging a nonaqueous electrolyte secondary cell containing a lithium-rich positive-electrode active material. When constant-current charging is performed to a predetermined voltage V2 which is equal to or higher than a setting voltage V1, and then constant-current discharging is performed to a predetermined voltage V3, V3<V1≤V2 is satisfied. Cell capacity C1 at V1, cell capacity C2 at V2, and cell capacity C3 at V3 satisfy 0.99C1≤C3<C2.

The non-aqueous electrolyte secondary cell according to the present invention comprises: an electrode body constituted by a positive electrode including a positive electrode active material comprising a lithium-containing transition metal oxide, a negative electrode including a negative electrode current collector onto which metallic lithium is deposited during charging, and a separator disposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte. The molar ratio of the total lithium content of the positive electrode and the negative electrode to the transition metal content of the positive electrode is 1.1 or less. During discharging, the positive electrode capacitance α(mAh) of the positive electrode and the volume X (mm.sup.3) of a hollow constituted by a space formed in the center of the electrode body 14 satisfy the relationship 0.5≤X/α≤4.0.

Battery packs having jelly roll battery cells of different designs or capacities may have an imbalance in the charging and/or discharging current supplied to and provided by each jelly roll due to differences in capacity specific impedance between the battery cells of the battery pack. A C-rate (i.e., current relative to rated capacity) of a first and second battery cell connected in parallel may be balanced by altering properties of an active layer and/or a thickness of a current collector of the second battery cell to reduce an impedance of the second battery cell.

The present disclosure provides a lithium-rich negative electrode plate, an electrode assembly and a lithium-ion battery, the lithium-rich negative electrode plate comprises a negative electrode collector and a negative electrode film, the negative electrode film is provided on a surface of the negative electrode collector and comprises a negative electrode active material, the lithium-rich negative electrode plate further comprises a layer of lithium metal provided on a surface of the negative electrode film. The negative electrode film further comprises a cyclic ester which is capable of forming a film on the negative electrode plate, a dielectric constant of the cyclic ester is larger than or equal to 10, and a reduction potential of the cyclic ester relative to Li/Li.sup.+ is lower than or equal to 1.5V.

The present technology relates to a method of managing a sliding region of an electrode, and the method includes: determining a specific region where a positive electrode and a negative electrode, which are subjects of management to be used in manufacturing an electrode assembly, face each other and setting a measurement location in the specific region; measuring a thickness and a loading amount of each electrode mixture layer of the positive electrode and the negative electrode at the set measurement location; measuring a thickness and a loading amount of an electrode mixture layer at each central portion of the positive electrode and the negative electrode; and calculating a ratio of the thickness of the electrode mixture layer of the positive electrode and the negative electrode to the thickness of the central portion.

A lithium secondary battery is disclosed herein. In some embodiment, a lithium secondary battery which includes a positive electrode including a positive electrode material mixture layer, wherein the positive electrode material mixture layer has a loading capacity of 3.7 mAh/cm.sup.2 to 10 mAh/cm.sup.2, a negative electrode including a negative electrode material mixture layer, a separator disposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte solution including a lithium salt, an organic solvent, and a compound represented by Formula 1, the concentration of the lithium salt in the non-aqueous electrolyte solution is 1.5 M to 3 M, the organic solvent is a mixed solvent including a cyclic carbonate-based organic solvent and a linear carbonate-based organic solvent, and the compound represented by Formula 1 is included in an amount of 0.1 wt % to 5 wt % based on a total weight of the non-aqueous electrolyte solution.