Composite Cathode Material Balancing Battery Output and Stability
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Solution Overview
Problem
Existing lithium secondary battery cathode active materials face issues with chemical stability and ionic conductivity, leading to insufficient high output characteristics.
Innovation Solution
A cathode active material comprising first particles of lithium metal oxide with a specific cobalt molar ratio and second particles of lithium phosphate compound, in a defined weight ratio, to enhance chemical stability and output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If NCM-based active material is used, then high output characteristics are achieved, but chemical stability deteriorates
Solution Approach 1:
The patent uses a composite cathode active material consisting of LiNi0.75Co0.05Mn0.20O2 (NCM) and LiFePO4 (LFP) in a weight ratio of 9:1 to 1:9. This composite structure combines the high output characteristics of NCM with the excellent chemical stability of LFP, resolving the contradiction between power and reliability.
2Reliability
If LFP-based active material is used, then chemical stability is improved, but ionic conductivity decreases
Solution Approach 1:
The patent combines LFP with NCM in a composite structure where LFP provides chemical stability and NCM provides high ionic conductivity. The synergistic effect of the composite material resolves the contradiction between reliability and productivity.
3Power
If cobalt content is increased, then output characteristics are improved, but production cost increases
Solution Approach 1:
The patent optimizes the cobalt content in the NCM component to 0.05 moles, representing a significant reduction from conventional high-cobalt formulations. This parameter optimization maintains adequate output characteristics while substantially reducing production costs associated with cobalt material.
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
The lithium secondary battery achieves improved capacity, lifespan, and stability while reducing production costs, suitable for green technology applications.
Implementation Method 1
The lithium secondary battery may store an electric energy by a difference in chemical potential when lithium ions are intercalated and deintercalated between a cathode and an anode
Implementation Method 2
The lithium secondary battery may store an electric energy by a difference in chemical potential when lithium ions are intercalated and deintercalated between a cathode and an anode
Data Source
AI summary
A cathode active material for a lithium secondary battery according to the embodiments of the present disclosure includes: first cathode active material particles which includes a lithium metal oxide containing nickel, cobalt and manganese; and second cathode active material particles which includes a lithium phosphate compound, wherein a molar ratio of the cobalt based on a total number of moles of the nickel, cobalt and manganese in the first cathode active material particles may be more than 0 and less than 0.15, and a weight ratio of the first cathode active material particles and the second cathode active material particles may be 20:80 to 80:20. Accordingly, a lithium secondary battery having improved stability, capacity characteristics, and lifespan characteristics while reducing production costs may be implemented.