Nonaqueous Battery Container Geometry for Energy Density
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Solution Overview
Problem
Nonaqueous electrolyte batteries with lithium titanium oxide as a negative electrode active material face challenges in achieving high energy density while maintaining safety and thermal stability, as they tend to have lower energy density compared to lithium-ion batteries and are prone to thermal runaway due to abnormal heat generation.
Innovation Solution
A nonaqueous electrolyte battery design featuring a container with a specific height-to-width-to-thickness ratio (0.15 ≤ Tmin/Tmax ≤ 1) and using a positive electrode active material with the composition Li1-aNi x Co y Mn z O2 and a spinel type lithium titanium oxide as the negative electrode, which enhances safety and volume energy density by optimizing thermal stability and reducing the number of cells required in a battery pack.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium titanium oxide is used as a negative electrode active material to improve safety, then safety is improved, but energy density deteriorates
Solution Approach 1:
The patent changes the physical parameters of the battery container by controlling the ratio between minimum dimension (Tmin) and maximum dimension (Tmax) to be within 0.15-0.65. This geometric parameter change optimizes the spatial arrangement of electrodes and electrolyte, improving volume energy density while maintaining the safety benefits of lithium titanium oxide negative electrode material.
2Stability of the object's composition
If lithium titanium oxide is used as a negative electrode active material to improve thermal stability, then thermal stability is improved, but the battery is prone to thermal runaway due to abnormal heat generation
Solution Approach 1:
The patent optimizes the container geometry by controlling the Tmin/Tmax ratio within 0.15-0.65, which improves heat dissipation characteristics and prevents abnormal heat generation leading to thermal runaway, while maintaining the inherent thermal stability of lithium titanium oxide.
3Quantity of substance
If the container dimensions are optimized to increase volume energy density, then volume energy density is improved, but the battery pack becomes more complex
Solution Approach 1:
The patent establishes a specific parameter range for container dimensions (Tmin/Tmax ratio between 0.15-0.65) that optimizes volume energy density. This clear parameter specification simplifies the design and manufacturing process, reducing complexity despite the optimized geometry requirements.
Data Source
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AI summary
According to one embodiment, a nonaqueous electrolyte battery includes a container (1), a positive electrode (6), and a negative electrode (7). The container (1) satisfies Formula (1) of 0.15 ≤ (Tmin/Tmax) ≤ 1. The positive electrode (6) includes a positive electrode active material represented by the composition formula Li1-aNixCoyMnzO2. The negative electrode (7) includes a spinel type lithium titanium oxide. A nominal capacity of the nonaqueous electrolyte battery is in a range of from 5 Ah to 200 Ah. When a state of charge based on the nominal capacity is 50%, an open circuit voltage is in a range of from 2.12 V to 2.24 V.