Carbon Negative Active Material for Li-Ion Cycle and Rate Performance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium-ion batteries face challenges in simultaneously improving energy density, cycle performance, and rate performance, with existing active materials failing to effectively enhance these aspects.
Innovation Solution
A negative active material with a carbon component is developed, characterized by specific graphitization degree and K value ranges, along with defined crystal size and orientation ratios, which optimizes lithium ion insertion and extraction processes, leading to improved electrochemical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional active materials are used in lithium-ion batteries, then the battery can operate with standard energy density and cycle life, but the energy density, cycle performance, and rate performance cannot be simultaneously improved
Solution Approach 1:
The patent applies parameter changes by precisely controlling the graphitization degree (Gr) of the carbon material within 0.90-0.98 and the K value within 0.05-0.15. These parameter optimizations enable the negative active material to achieve high energy density while maintaining excellent cycle performance and rate performance, resolving the contradiction between these three parameters that plagues conventional active materials
Solution Approach 2:
The patent uses composite carbon materials with specific graphitization degrees and controlled crystalline structures (La/S and Lc/S ratios) to create a negative active material that combines the advantages of different carbon forms. This composite approach allows simultaneous improvement of energy density, cycle performance, and rate performance, overcoming the limitations of single-component conventional materials
2Productivity
If the graphitization degree of carbon material is increased to improve electrochemical performance, then energy density and rate performance improve, but manufacturing complexity and control difficulty increase
Solution Approach 1:
The patent defines specific parameter ranges for graphitization degree (0.90-0.98) and K value (0.05-0.15) that optimize rate performance while providing clear manufacturing targets. These quantified parameters transform the complex graphitization control process into a manageable specification system, reducing manufacturing complexity despite the high performance requirements
3Duration of action of stationary object
If the crystal orientation ratios (La/S and Lc/S) are optimized to improve lithium ion insertion and extraction, then cycle capacity retention rate improves, but the complexity of material characterization and quality control increases
Solution Approach 1:
The patent establishes specific crystal orientation ratio ranges (La/S: 15-30, Lc/S: 5-15) that optimize lithium ion insertion and extraction kinetics, thereby improving cycle capacity retention. By defining these clear numerical ranges, the patent simplifies quality control and characterization procedures, making the measurement and control of crystal orientation practical despite the inherent complexity of the process
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 optimized negative active material significantly enhances the energy density, cycle capacity retention rate, and rate performance of lithium-ion batteries, while reducing lithium plating and cycle expansion, thereby improving overall battery performance.
Implementation Method 1
optimizes lithium ion insertion and extraction processes, leading to improved electrochemical performance
Data Source
AI summary
A negative active material includes a carbon material. The carbon material satisfies the following relationship: 6<Gr/K<16, Gr is a graphitization degree of the carbon material, measured by X-ray diffraction; and K is a ratio Id/Ig of a peak intensity Id of the carbon material at a wavenumber of 1250 cm−1 to 1650 cm−1 to a peak intensity Ig of the carbon material at a wavenumber of 1500 cm−1 to 1650 cm−1, and is measured by using Raman spectroscopy, and K is 0.06 to 0.15.