Battery Electrode Composition for Uniform Li-Ion Conduction
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Solution Overview
Problem
Secondary batteries, such as lithium-ion batteries, face challenges in achieving rapid charge/discharge performance and long-term reliability for vehicle applications due to high lithium ion conductive resistance, which is exacerbated by the aggregation of fine inorganic solid particles that reduce their uniform distribution within the active material-containing layer.
Innovation Solution
Incorporating inorganic solid particles with lithium ion conductivity and a carbon material into the active material-containing layer, with specific pore size and volume ratios to minimize lithium ion conductive resistance and promote uniform dispersion, thereby enhancing input/output performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If fine inorganic solid particles are mixed into the active material-containing layer to reduce lithium ion conductive resistance, then input/output performance is improved, but the particles aggregate and distribution uniformity deteriorates
Solution Approach 1:
A solid polymer electrolyte is introduced as an intermediary substance between the inorganic solid particles and the active material. This polymer electrolyte has high lithium ion conductivity and acts as a matrix that disperses and stabilizes the fine inorganic particles, preventing their aggregation while maintaining efficient lithium ion transport pathways throughout the active material-containing layer.
Solution Approach 2:
The patent creates a composite structure within the active material-containing layer by combining three key components: inorganic solid particles (for lithium ion conductivity), solid polymer electrolyte (for dispersion and ion transport), and active material. This composite approach leverages the complementary properties of each material to achieve both uniform distribution and high input/output performance.
2Loss of time
If rapid charge/discharge capability is enhanced through material composition, then charging time is reduced, but lithium ion conductive resistance increases
Solution Approach 1:
The patent optimizes the particle size parameters of the inorganic solid particles, specifying a diameter of 0.1 μm to 10 μm with particular preference for 0.1 μm to 1 μm. This parameter control ensures sufficiently small particles for high surface area and fast ion transport (enabling rapid charging) while being large enough to prevent excessive aggregation. The solid polymer electrolyte content is also optimized at 10 wt% to 50 wt% to balance ion conductivity with structural stability.
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 proposed electrode design achieves reduced lithium ion conductive resistance and improved charge/discharge efficiency, leading to enhanced input/output performance and extended battery life for secondary batteries used in vehicles.
Implementation Method 1
inorganic solid particles having lithium ion conductivity
Implementation Method 2
A pore size diameter D1 at a first peak is 0.05 μm to 10 μm. A first pore volume corresponding to the first peak is 20% to 50% with respect to a total pore volume within the active material-containing layer.
Data Source
AI summary
According to one embodiment, provided is an electrode including an active material-containing layer that includes an active material, inorganic solid particles having lithium ion conductivity, and a carbon material. The active material-containing layer has a first peak corresponding to a maximum log differential intrusion in a log differential intrusion distribution curve according to mercury porosimetry. A pore size diameter D1 at the first peak is 0.05 μm to 10 μm. A first pore volume corresponding to the first peak is 20% to 50% with respect to a total pore volume within the active material-containing layer. A ratio of a second pore volume in a range of 0.005 μm to 0.02 μm relative to the first pore volume is 0.1% to 5%.