Composite Positive Electrode Material for High-Rate Discharge
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Solution Overview
Problem
Existing lithium ion secondary battery positive electrodes face challenges in achieving high-rate discharge characteristics due to insufficient conductivity and poor arrangement of conductive materials, leading to blocked ion paths and inadequate performance in high-rate discharge applications.
Innovation Solution
A composite positive electrode material is developed by mixing a conductive material with a specific aspect ratio, dispersing the positive electrode active material and conductive material in a solvent, and then agglutinating them to form composite particles with enhanced conductivity and ion diffusion pathways.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive materials are added to enhance conductivity, then electrical conductivity is improved, but ion diffusion paths become blocked
Solution Approach 1:
The patent applies local quality by creating distinct functional zones: conductive materials are concentrated at particle surfaces and interfaces to maximize electrical conductivity where electrons are transferred, while the interior porous structure remains open for ion diffusion. This spatial differentiation of material properties resolves the contradiction between conductivity enhancement and ion diffusion maintenance.
Solution Approach 2:
The patent implements a nested structure where conductive material particles are embedded within or on the surface of active material particles, creating a core-shell or surface-coated configuration. This nesting allows the conductive material to provide electrical pathways while the surrounding porous structure maintains ion diffusion channels, simultaneously achieving both conductivity improvement and ion diffusion preservation.
2Reliability
If fine composite structure is created to improve conductivity, then electrical conduction is enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent merges multiple functions into a single composite particle structure: the active material particles themselves serve as both the energy storage medium and the structural framework, while conductive materials are integrated directly onto their surfaces. This consolidation eliminates the need for separate conductive additive layers and complex multi-layer structures, reducing manufacturing complexity while maintaining enhanced electrical conduction.
Solution Approach 2:
The patent employs composite materials by combining active material and conductive material into a unified composite particle system. This composite structure inherently provides both electrochemical activity and electrical conductivity without requiring additional processing steps or complex assembly procedures, thus enhancing electrical conduction while keeping the structure relatively simple for manufacturing.
3Reliability
If conductive material coverage is increased to reduce resistance, then electrical resistance is reduced, but ion diffusion paths are blocked
Solution Approach 1:
The patent applies partial action by using a controlled, moderate amount of conductive material coverage rather than complete coating. The conductive material is applied just sufficient to create effective electrical pathways at critical interfaces, leaving the majority of the particle surface and internal porosity available for ion diffusion. This partial coverage approach reduces electrical resistance without excessively blocking ion diffusion paths.
Solution Approach 2:
The patent transitions from two-dimensional surface coating to three-dimensional integrated structures where conductive materials form networks both on the surface and within the particle interior. This dimensional expansion creates electrical pathways through multiple routes (surface conduction and internal conduction) without requiring extensive surface coverage that would block ion diffusion, thus reducing resistance while preserving ion access.
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 composite material significantly improves high-rate discharge characteristics by increasing contact points between the active material and conductive material, forming effective conductive paths, and allowing smoother ion diffusion, resulting in higher electric current flow during discharge.
Implementation Method 1
conductive paths between the positive electrode active materials
Implementation Method 2
electric discharge is advanced by the operation of lithium ions diffused to the positive electrode side
Data Source
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AI summary
The present invention provides a composite positive electrode material for a lithium ion battery, which is particularly excellent in high-rate discharge characteristics in a battery, and also provides a slurry, positive electrode and battery using the composite positive electrode material. The composite positive electrode material for a lithium ion battery contains: a positive electrode active material (a); a conductive material (b) having a primary particle diameter of 10 to 100 nm and/or a fibrous conductive material (c) having a fiber diameter of 1 nm to 1 µm; and a conductive material (d) having an aspect ratio of 2 to 50, wherein the composite positive electrode material for a lithium ion battery is obtained by mixing the conductive material (d) with a composition containing the positive electrode active material (a), and the conductive material (b) and/or the conductive material (c), the composition obtained by dispersing the positive electrode active material (a), and the conductive material (b) and/or the conductive material (c) in a solvent to a state where the positive electrode active material (a), and the conductive material (b) and/or the conductive material (c) are forcibly dispersed, and then agglutinating the positive electrode active material (a), and the conductive material (b) and/or the conductive material (c) .