POSITIVE ELECTRODE MATERIAL WITH HIGH COMPACTED DENSITY AND ELECTROCHEMICAL ENERGY STORAGE DEVICE

The present invention relates to the field of battery technologies, and in particular, to a high-compacted-density positive electrode material and an electrochemical energy storage apparatus. The positive electrode material includes a lithium-nickel transition metal oxide A and a lithium-nickel transition metal oxide B. The lithium-nickel transition metal oxide A is secondary particles, whose chemical formula is shown in formula I: Lia1(Nib1Coc1Mnd1)x1M1-x1O2-e1Xe1. The lithium-nickel transition metal oxide B is a monocrystalline structure or a monocrystalline-like structure, whose chemical formula is shown in formula II: Lia2(Nib2Coc2Mnd2)x2M'1-x2O2-e2X'e2 (II). The positive electrode material of the present invention includes the large-particle lithium-nickel transition metal oxide A and the small-particle lithium-nickel transition metal oxide B to improve an energy density of the battery. A degree of crystallinity and particle size distribution of the mixed positive electrode material can improve a compacted density of the high-nickel active material, and ensure lower gassing and good cycle performance.