Composite Current Collector Structure for Higher Battery Volume Energy Density
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Solution Overview
Problem
Traditional lithium-ion batteries have a low effective energy-to-volume ratio due to the large volume of cathode and anode current collectors, which occupy significant space without contributing to energy storage.
Innovation Solution
A composite current collector is designed with a substrate layer and two metal material layers, each coated with opposite polarity active materials, allowing for a thin structure that enhances energy storage capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional separate cathode and anode current collectors are used, then structural stability and electrical conductivity are ensured, but the effective energy-to-volume ratio decreases due to large occupied volume
Solution Approach 1:
The patent combines the cathode current collector and anode current collector into a single integrated bipolar current collector structure. The bipolar current collector has a first surface for cathode active material and a second surface for anode active material, eliminating the need for separate current collectors and separators. This merging reduces the overall volume occupied by current collectors while maintaining structural stability and electrical conductivity for both electrodes.
Solution Approach 2:
The bipolar current collector serves multiple functions simultaneously: it acts as the current collector for both the cathode and anode, provides mechanical support for both electrodes, and functions as the separator between the two electrodes. This multi-functionality reduces the total component count and volume while ensuring structural stability and electrical conductivity for both electrodes.
2Reliability
If bipolar current collector with aluminum cathode layer and copper anode layer is used, then electrical conductivity is improved, but volume energy density decreases and surface density increases
Solution Approach 1:
The patent optimizes the thickness parameters of the metal layers in the bipolar current collector. By reducing the thickness of the aluminum cathode layer and copper anode layer to minimal required values while maintaining electrical conductivity, the volume occupied by non-energy-storing materials is reduced. This parameter optimization improves volume energy density while preserving the electrical conductivity needed for reliable battery operation.
Data Source
AI summary
A composite current collector and a manufacturing method therefor, a composite electrode sheet and a manufacturing method therefor, and a lithium battery are provided. The composite current collector includes: a substrate layer; a first metal material layer, which is arranged on one side of the substrate layer, and is to be coated with a first active material on the side away from the substrate layer; and a second metal material layer, which is arranged on the side of the substrate layer away from the first metal material layer, and is to be coated with a second active material on the side away from the substrate layer, with the polarity of the second active material being opposite to the polarity of the first active material.