Nonaqueous Electrolyte Battery with Stabilized Spinel Electrodes
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Solution Overview
Problem
Nonaqueous electrolyte batteries face issues with capacity degradation and increased resistance during charging and discharging cycles, along with excessive gas generation, particularly with spinel-type lithium manganese composite oxides as positive electrodes and lithium titanium composite oxides as negative electrodes.
Innovation Solution
Incorporating a positive electrode with a lithium manganese composite oxide (Li 1-x Mn 2-y-z Al y M z O 4) and a negative electrode with a mixture of Li 4+a Ti 5 O 12 and a second oxide (300 ppm to 5000 ppm) selected from Al, Co, Cr, Cu, Fe, Mg, Ni, and Zr, which improves crystal structure and suppresses gas generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If spinel-type lithium manganese composite oxides are used as positive electrode active materials, then battery capacity is improved, but capacity degradation increases under high temperature environment during repeated charging and discharging
Solution Approach 1:
The patent applies local quality by substituting specific metal elements (Al, Co, Ni, Mn, Zn) at controlled ratios in the spinel structure to improve local stability while maintaining overall capacity. The positive electrode uses Li1-xMn2-yAl yMzO4 where foreign metals are strategically placed to stabilize the crystal structure against high-temperature degradation.
Solution Approach 2:
The patent employs composite materials by combining spinel-type lithium manganese composite oxide with foreign metals (Al, Co, Ni, Mn, Zn) to create a hybrid structure that leverages the high capacity of Mn-based materials while incorporating the structural stability of substituted metals, achieving both capacity and reliability improvement.
2Reliability
If spinel-type lithium titanium composite oxides are used as negative electrode active materials, then structure stability and reliability are improved, but gas generation increases during battery operation
Solution Approach 1:
The patent uses an amorphous coating layer as an intermediary between the spinel-type lithium titanium composite oxide particles and the electrolyte. This coating layer, containing Li, P, and Si, acts as a buffer that prevents direct harmful interactions while maintaining the structural stability of the underlying spinel material, thereby reducing gas generation.
Solution Approach 2:
The patent applies a thin amorphous coating film on the surface of the negative electrode particles. This flexible shell structure accommodates volume changes during cycling while protecting the core spinel material from electrolyte decomposition, thus maintaining reliability and suppressing gas generation.
3Reliability
If the amount of foreign metal substitution in lithium manganese composite oxide is increased to improve crystal structure, then capacity degradation is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent optimizes substitution ratios within specific ranges (0 < y ≤ 0.5, 0 < z ≤ 0.1) to achieve the minimum effective foreign metal content needed for structural stabilization. This parameter optimization balances capacity retention improvement with manufacturing simplicity, avoiding excessive complexity while maintaining reliability.
Data Source
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AI summary
According one an embodiment, a nonaqueous electrolyte battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte is provided. The positive electrode includes an active material including Li1-xMn2-y-zAlyMzO4 (-0.1 ≤ x ≤ 1, 0.20 ≤ y ≤ 0.35, 0 ≤ z ≤ 0.1, M is at least one metal selected from the group consisting of Mg, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, and Sn). The negative electrode includes an active material including a first oxide represented by Li4+aTi5O12 (-0.5 ≤ a ≤ 3) and a second oxide of at least one element selected from the group consisting of Al, Co, Cr, Cu, Fe, Mg, Ni, Zn, and Zr. In the active material of the negative electrode, the second oxide is included in an amount of from 300 ppm to 5000 ppm relative to a weight of the first oxide.