Lithium Battery NCM-SiOx Electrodes for Energy Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithium secondary batteries face challenges in increasing energy density and improving high-output performance due to limitations in positive and negative electrode materials, particularly with nickel-rich materials causing thermal instability and graphite having low capacity per unit mass.
Innovation Solution
A lithium secondary battery design combining specific types of active materials, particle diameters, and component contents, using lithium composite transition metal compounds with nickel, cobalt, and manganese, and silicon oxide as negative electrode materials, with controlled particle sizes to optimize performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If nickel content in the positive electrode active material is increased to improve capacity, then the energy density is improved, but thermal stability deteriorates and side reactions increase
Solution Approach 1:
The patent applies parameter changes by precisely controlling the nickel content within 80-95 mol% and manganese content within 0.5-15 mol% in the NCM-based composite transition metal compound. This optimization balances the capacity enhancement from high nickel content with thermal stability maintenance through controlled manganese content, resolving the contradiction between energy density improvement and reliability preservation.
Solution Approach 2:
The patent uses composite materials by creating an NCM-based lithium composite transition metal compound where nickel, cobalt, and manganese are combined in specific ratios. The composite structure allows nickel to provide high capacity while manganese and cobalt contribute to thermal stability, effectively resolving the contradiction between improved capacity and maintained thermal stability through material composition design.
2Device complexity
If graphite is used as negative electrode active material, then the battery structure is simple, but the capacity per unit mass is low
Solution Approach 1:
The patent applies local quality by using graphite as the primary negative electrode material to maintain structural simplicity, while locally introducing silicon oxide at specific sites within the electrode structure. This allows the majority of the electrode to retain the simple graphite structure while specific regions provide enhanced capacity through silicon oxide, resolving the contradiction between structure simplicity and capacity enhancement.
3Quantity of substance
If non-carbon-based negative electrode materials are used to increase capacity, then the energy density is improved, but initial efficiency decreases and irreversible capacity loss increases
Solution Approach 1:
The patent applies partial action by incorporating silicon oxide in a controlled amount of 5-50 wt% rather than using it as the sole negative electrode material. This partial incorporation provides capacity enhancement while limiting the negative effects of low initial efficiency and high irreversible capacity loss associated with pure non-carbon materials, effectively balancing capacity improvement with efficiency maintenance.
4Quantity of substance
If the battery is designed for high capacity, then the energy density is improved, but the battery volume increases
Solution Approach 1:
The patent applies parameter changes by optimizing the particle size of the positive electrode active material to have an average particle diameter of 1-10 μm. This size optimization increases the surface area to volume ratio, improving capacity utilization and energy density while preventing excessive battery volume expansion, thus resolving the contradiction between high capacity and compact size.
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 design enhances energy density and improves high-output performance and battery cycle life by reducing side reactions and diffusion resistance, while maintaining structural integrity.
Implementation Method 1
a state in which an organic electrolytic solution or a polymer electrolytic solution is filled between a positive electrode and a negative electrode each made of an active material capable of intercalation and deintercalation of lithium ions, electrical energy is produced by oxidation/reduction reactions at a time when lithium ions are intercalated/deintercalated into/from the positive electrode and the negative electrode
Implementation Method 2
electrical energy is produced by oxidation/reduction reactions at a time when lithium ions are intercalated/deintercalated into/from the positive electrode and the negative electrode
Data Source
AI summary
The present invention relates to a lithium secondary including: a positive containing a positive electrode active material; a negative electrode containing a negative electrode active material; a separator provided between the positive electrode and the negative electrode; and an electrolyte, wherein the positive electrode active material includes a lithium composite transition metal compound including nickel (Ni), cobalt (Co), and manganese (Mn); the lithium composite transition metal compound includes at least one of single particles and quasi-single particles, the average particle diameter (D50 =) of the at least one of the single particle and the pseudo-single particle having an average particle diameter (D50) of 1 µm to 10 µm (both inclusive); the single particle is composed of one nodule and the pseudo-single particle is a composite composed of 30 or less nodules; and the negative electrode active material includes silicon oxide represented by SiOx (0<x<2), the silicon oxide represented by SiOx (0<x<2) having an average particle diameter (D50) of 1 µm or greater, and at least one of the single particles and pseudo-single particles having an average particle diameter (D50) smaller than the average particle diameter (D50) of the silicon oxide represented by SiOx(0<x<2).