High-Ni Cathode Electrode Thermal Stability via Dielectric Oxide
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Solution Overview
Problem
Lithium-ion secondary batteries with high Ni content positive electrode active materials face a reduction in thermal stability, which is a challenge for achieving high volumetric energy density without compromising thermal stability.
Innovation Solution
Incorporating a high-dielectric oxide solid and an electrolytic solution in a specific volume ratio within the electrode material mixture layer, along with an aprotic polar solvent, to stabilize the electrode and maintain thermal stability while achieving high energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a high Ni content positive electrode active material is used to increase volumetric energy density, then the volumetric energy density is improved, but the thermal stability is reduced
Solution Approach 1:
The patent uses a composite material system consisting of high Ni content positive electrode active material (LiNi0.8Co0.15Al0.05O2) combined with a specific electrolytic solution formulation. The electrolyte contains multiple components (LiPF6 salt in a mixture of cyclic carbonates and chain carbonates) that work together to stabilize the high Ni material, enabling it to maintain both high energy density and thermal stability through synergistic material interactions
Solution Approach 2:
The patent optimizes specific parameters of the electrolytic solution including the concentration of LiPF6 (0.5-2.0 mol/L), the volume ratio of cyclic to chain carbonates (3:7 to 1:1), and the presence of specific additives. These parameter adjustments to the electrolyte composition enable the high Ni content cathode material to achieve both high volumetric energy density and improved thermal 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 solution enables lithium-ion secondary batteries to maintain high volumetric energy density without reducing thermal stability, even with high Ni content positive electrode active materials, enhancing their performance and durability.
Implementation Method 1
an electrode material mixture layer including an electrode active material, a high-dielectric oxide solid, and an electrolytic solution
Implementation Method 2
The electrolytic solution may contain an aprotic polar solvent with a boiling point of 150° C. or more
Implementation Method 3
The electrode material mixture layer may have a differential scanning calorimetry (DSC) curve with a reduction in exothermic peak at 270° C.
Data Source
AI summary
Provided are: an electrode for a lithium-ion secondary battery, said electrode enabling a battery having a high volumetric energy density to be attained, without reducing heat stability, even if a positive electrode active material that contains a high percentage of Ni is used; and a lithium-ion secondary battery that uses the positive electrode. An electrolyte and highly-dielectric solid particles are present in an electrode mixture layer at a specific volume ratio. Specifically, the electrode for a lithium-ion battery is configured such that the electrode mixture layer includes an electrode active material, a highly-dielectric solid oxide, and an electrolyte, wherein the volume ratio of the electrolyte and the highly-dielectric solid oxide in the electrode mixture layer is set in the range of 99:1 to 76:24.