High-Nickel Battery KEL Control for Energy Density and Cycle Life
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Solution Overview
Problem
Existing batteries with high nickel content positive electrode materials face challenges in balancing energy density and cycle performance, leading to potential issues such as electrode expansion and reduced cycle life.
Innovation Solution
A battery design incorporating a positive electrode material with a specific chemical formula Lix(NiaCObMnc)1−dMdO2−yAy, optimized KEL (1.6 g/Ah ≤ KEL ≤ 1.9 g/Ah) and space utilization rate (≥0.8), along with tailored negative electrode and current collector dimensions, and the use of single crystal particles and a primer layer to enhance energy density and cycle performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If positive electrode materials with high nickel content are used, then energy density is improved, but cycle performance deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the chemical composition parameters of the positive electrode material (LiNi0.6Co0.2Mn0.2O2 with specific doping elements) and the KEL ratio (1.4-1.8 g/Ah) to achieve both high energy density and good cycle performance. This resolves the contradiction by optimizing the material parameters rather than simply increasing nickel content.
Solution Approach 2:
The patent uses composite materials by combining LiNi0.6Co0.2Mn0.2O2 positive electrode material with graphite and lithium iron phosphate negative electrode materials. This composite approach allows the battery to achieve high energy density while maintaining structural stability and cycle performance through the complementary properties of different materials.
2Use of energy by moving object
If space utilization rate is increased to improve energy density, then battery volume efficiency is improved, but internal pressure risk increases
Solution Approach 1:
The patent applies parameter changes by optimizing the space utilization rate to a specific range (0.75-0.85) rather than maximizing it. This controlled optimization allows high energy density while maintaining sufficient internal space for electrolyte distribution and accommodating thermal expansion, thus preventing internal pressure issues.
Solution Approach 2:
The patent uses the electrolyte as an intermediary substance that fills the spaces between electrode plates. The electrolyte not only enables ion transport but also acts as a buffer that accommodates volume changes and reduces internal pressure, allowing high space utilization without pressure risks.
3Use of energy by moving object
If KEL ratio is optimized to improve energy density, then battery performance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent transforms the manufacturing challenge by defining a wide optimal range for KEL (1.4-1.8 g/Ah) rather than specifying a narrow target value. This parameter range approach allows manufacturers to achieve high energy density while maintaining reasonable manufacturing precision, as any value within the range delivers good performance.
Data Source
AI summary
The present application provides a battery and an electrical apparatus. The battery comprises a case, an electrode assembly and an electrolyte solution. The case is provided with an accommodating cavity inside, and the electrode assembly and the electrolyte solution are both arranged within the accommodating cavity. The electrode assembly comprises a positive electrode plate comprising a positive electrode current collector and a positive electrode active layer located on at least one surface of the positive electrode current collector. The positive electrode active layer comprises a positive electrode active material having a chemical formula of Lix(NiaCObMnc)1−dMdO2−yAy; the KEL of the battery satisfies 1.6 g/Ah≤KEL≤1.9 g/Ah, KEL represents the ratio of the mass of free electrolyte solution to the rated capacity of the battery, in units of g/Ah; and the space utilization rate η of the battery is ≥0.8.