Positive Electrode Composite Carbon Structure for High-Rate Capacity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electrochemical devices, such as lithium-ion batteries, face limitations in rate performance and energy density despite improvements, requiring further enhancements for better lithium ion transport and capacity retention.
Innovation Solution
The electrochemical device incorporates a positive electrode active material layer with a composite carbon material, including carbon nanotubes and two-dimensional inorganic materials, which provides structural bonding and pore formation, optimizing pore ratios for enhanced lithium ion transport and energy density, while using a composite carbon material as a binder to replace traditional polymer binders, making the manufacturing process more environmentally friendly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional polymer binders are used in the positive electrode, then structural bonding is achieved, but the manufacturing process is less environmentally friendly and energy intensity is reduced
Solution Approach 1:
The patent removes traditional polymer binders from the electrode structure and replaces them with a binder-free design where active material particles are directly connected through conductive carbon networks, eliminating harmful chemicals and reducing manufacturing energy requirements
Solution Approach 2:
The patent changes the fundamental parameter of electrode composition by eliminating polymer binder content to near zero and replacing it with conductive carbon structures that provide both electrical connectivity and mechanical integrity, fundamentally altering the manufacturing process
2Quantity of substance
If the positive electrode has high active material content, then energy density is improved, but lithium ion transport becomes restricted due to insufficient pores
Solution Approach 1:
The patent incorporates porous conductive carbon structures with controlled pore sizes (0.003-2 μm) that create efficient lithium ion transport channels while maintaining high active material content, allowing rapid ion diffusion through the electrode matrix
Solution Approach 2:
The patent creates a composite structure combining active material particles with conductive carbon networks and porous frameworks, where the composite architecture provides both high density and efficient ion transport pathways simultaneously
3Speed
If the pore diameter in the positive electrode is small, then lithium ion transport paths are numerous, but the volume ratio of pores to total volume becomes excessive reducing active material content
Solution Approach 1:
The patent applies different pore size distributions in different regions of the electrode structure, with smaller pores (0.003-0.2 μm) providing numerous transport paths and larger pores (0.2-2 μm) maintaining structural integrity, optimizing both ion transport and active material content locally
Data Source
AI summary
An electrochemical device includes a positive electrode, the positive electrode includes a positive electrode active material layer, the positive electrode active material layer includes a positive electrode active material and a composite carbon material. A is a volume of the positive electrode active material layer, B is a volume of pores having a pore diameter of less than 2 μm in the positive electrode active material layer, and 14%≤B/A≤20%. The positive electrode active material layer includes the positive electrode active material and the composite carbon material, and 14%≤B/A≤20%, and indicates that the formed positive electrode has abundant pores for lithium ion transport.