Patent ID: 11923541
Assignee: ASAHI KASEL KABUSHIKI KAISHA
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
1. A lithium ion secondary battery provided with a positive electrode, a negative electrode and a nonaqueous electrolyte containing lithium ions; wherein,
the positive electrode has a positive electrode current collector and a positive electrode active material layer provided on one side or both sides of the positive electrode current collector,
the positive electrode active material layer contains a positive electrode active material and a lithium compound other than the positive electrode active material,
the positive electrode active material contains a transition metal oxide that is capable of occluding and releasing lithium ions and contains Ni atoms,
the concentration of the lithium compound other than the positive electrode active material contained in the positive electrode active material layer based on the total weight of the positive electrode active material layer is 0.1 wt % to 10 wt %,
the negative electrode has a negative electrode current collector and a negative electrode active material layer provided on one side or both sides of the negative electrode current collector,
the negative electrode active material layer, based on the total weight of the negative electrode active material layer, contains a carbon material as a first negative electrode active material at a ratio of 50 wt % to 60 wt %, at least one type among SiOx (wherein, 0.01≤x≤2) and tin dioxide as a second negative electrode active material at a ratio 30 wt % to 50 wt %,
a difference between energy of the Ni3p main peak and energy of the Ni3p sub-peak as measured by X-ray photoelectron spectroscopy (XPS) of the positive electrode active material layer when the voltage of the lithium ion secondary battery is 3.5 V, is 4.9 eV to 6.1 eV,
a relative concentration of F atoms, as measured by X-ray photoeclectron spectroscopy (XPS) of positive electrode active material layer when the voltage of the lithium ion secondary battery is 3.5 V, is 7.2 atomic % to 27.1 atomic %
the relative concentration of Li atoms having a peak at 52.5 eV to 53.7 eV in the Li1s spectrum observed by X-ray photelectron spectroscopy (XPS) of the negative electrode active material layer when the voltage of the lithium ion secondary battery is 3.5 V, is 1.0 atomic % to 25.0 atomic %, and
the relative concentration of F atoms, as measured by X-ray photelectron spectroscopy (XPS) of the negative electrode active material layer when the voltage of the lithium ion secondary battery is 3.5 V, is 7.5 atomic % to 46.5 atomic %.