High-Nickel Cathode Material for H2-H3 Phase Transition Control
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Solution Overview
Problem
Existing lithium secondary batteries face challenges in efficiently adjusting charge/discharge capacity and phase transitions due to variations in upper limit charge voltage requirements across different applications, leading to inefficiencies in battery design and performance.
Innovation Solution
A high-nickel lithium transition metal composite oxide-based positive electrode active material with controlled lattice volume and Curie-Weiss temperature, allowing precise adjustment of nickel occupancy in the lithium layer to manage H2-H3 phase transitions and voltage plateaus, thereby aligning designed capacity with actual capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the upper limit charge voltage is increased to enhance battery capacity, then the energy density improves, but the structural stability deteriorates due to H2-H3 phase transitions
Solution Approach 1:
The patent applies parameter changes by precisely controlling the lattice volume (101.0-102.0 ų) and Curie-Weiss temperature (-50 to 50 K) of the positive electrode active material. These parameter adjustments optimize the nickel occupancy in the lithium layer, enabling the material to maintain structural stability while achieving high energy density through controlled H2-H3 phase transition behavior at elevated voltages.
Solution Approach 2:
The patent employs composite materials by designing a lithium transition metal composite oxide with multi-element composition (Li, Ni, Co, Mn, Al, B) where each element serves a specific function. The composite structure allows synergistic effects that stabilize the lattice during phase transitions while maintaining high capacity, resolving the contradiction between energy density and structural stability.
2Quantity of substance
If the nickel content is increased to improve capacity, then the charge/discharge capacity increases, but the voltage control precision deteriorates
Solution Approach 1:
The patent uses parameter changes by establishing specific ranges for lattice volume (101.0-102.0 ų) and Curie-Weiss temperature (-50 to 50 K) that correlate with nickel occupancy (0.05-0.15). These parameter controls enable precise voltage management during H2-H3 phase transitions, allowing high capacity materials to operate with improved voltage control precision through material-level optimization.
3Quantity of substance
If the lattice volume is expanded to accommodate more lithium, then the capacity increases, but the phase transition control deteriorates
Solution Approach 1:
The patent applies parameter changes by defining an optimal lattice volume range (101.0-102.0 ų) that balances lithium accommodation capacity with phase transition control. This parameter optimization, combined with Curie-Weiss temperature control, ensures that the material can host sufficient lithium while maintaining sharp, controllable H2-H3 phase transitions for precise capacity management.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise control of charge/discharge capacity and phase transitions, ensuring battery performance meets specific customer requirements by optimizing material-level characteristics.
Implementation Method 1
Curie-Weiss temperature T satisfies following Equation 2: -50≤T≤50
Implementation Method 2
an H2-H3 structural phase transition
Data Source
AI summary
A positive electrode active material is characterized by being a high-nickel lithium transition metal composite oxide-based positive electrode active material having a layered structure, wherein a lattice volume V of the positive electrode active material satisfies following Equation 1, and Curie-Weiss temperature T satisfies following Equation 2:about 101.4 Å3≤V≤101.75 Å3[Equation 1]about 0 K≤T≤30 K[Equation 2]where the lattice volume V of the positive electrode active material is a value measured by X-ray powder diffraction (XRD), and the Curie-Weiss temperature is a value measured by a superconducting quantum interference device (SQUID).