Positive Electrode Active Material for Low-Resistance Li-Ion Batteries
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Solution Overview
Problem
Conventional positive electrode active materials face challenges in effectively incorporating specific additive elements into their crystal structures, hindering the improvement of battery resistance characteristics in lithium-ion batteries.
Innovation Solution
A positive electrode active material with a composition of LixNiaCObMncM1dM2eO2, where M1 and M2 elements are combined to facilitate their incorporation into the crystal structure, stabilizing the structure and inhibiting Ni-mixing during charging and discharging, thereby reducing battery resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additive elements are added to positive electrode active materials to improve resistance characteristics, then battery resistance characteristics should improve, but the additive elements have difficulty getting into the crystal structures
Solution Approach 1:
The patent uses a composite doping approach by combining two types of additive elements (M1 and M2) in the positive electrode active material. M1 elements (such as Al, Mg, La, Ti, Zn, B, W, Ni, Co, Fe, Cr, V, Ru, Cu, Cd, Ag, Y, Sc, Ga, In, As, Sb, Pt, Au, or Si) work synergistically with M2 elements (such as Li, Na, K, Ca, Sr, Ba, Pb, Bi, Po, Rn, or radioactive elements) to achieve effective incorporation into the crystal structure. This composite material strategy allows the additive elements to successfully enter the crystal lattice and improve battery resistance characteristics, overcoming the limitation of single-element doping that failed to effectively incorporate into the structure.
2Power
If nickel content is increased to improve battery performance, then power characteristics improve, but Ni-mixing occurs during charging and discharging causing resistance increase
Solution Approach 1:
The patent applies preliminary anti-action by incorporating additive elements M1 and M2 into the crystal structure before battery operation. These pre-incorporated elements create structural stabilization that prevents Ni-mixing during subsequent charging and discharging cycles. The additive elements act in advance to counteract the tendency of nickel layers to mix with lithium layers, thereby maintaining low resistance even when high nickel content (60 mol % or more) is used to achieve high power characteristics.
Solution Approach 2:
The patent combines high nickel content (a ≥ 0.6) with composite doping of M1 and M2 elements to create a stable crystal structure. The M1 elements (such as Al, Mg, La, Ti, Zn, B, W, Ni, Co, Fe, Cr, V, Ru, Cu, Cd, Ag, Y, Sc, Ga, In, As, Sb, Pt, Au, or Si) and M2 elements work together to stabilize the layered structure, preventing Ni-mixing even at high nickel concentrations. This composite material approach enables the battery to achieve both high power characteristics from high nickel content and low resistance through structural stabilization.
Data Source
AI summary
A positive electrode active material has a composition represented by LixNiaCObMncM1dM2eO2 and a TM interlayer distance (D) of 2.02 Å to 2.30 Å. In the composition, 0.1≤x≤1.5, 0.5≤a≤1.0, 0≤b≤0.3, 0≤c≤0.3, a+b+c=1.0, 0.0005≤d≤0.050, and 0.0005≤e≤0.050, M1 represents at least one type of element selected from the group including Ba, Pr, La, Y, Sr, Ce, Se, Hf, Rh, Zr, and Sn, and M2 represents at least one type of element selected from the group including W, Re, Sb, Sn, Ta, Os, Ir, Mo, Nb, Tc, Ru, Ga, Ag, Pd, Ge, As, Zr, In, Pt, Al, and Ti.