Lightweight Composite Current Collector for Li-Ion Batteries
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Solution Overview
Problem
Current lithium ion battery current collectors lack optimal weight energy density, volume energy density, and mechanical stability, which hinders the development of high-performance lithium ion batteries for electric vehicles and consumer electronics.
Innovation Solution
A current collector design featuring an insulation layer with a lower density than the conductive layer, supported by a metal protective layer, which enhances mechanical strength, prevents oxidation and corrosion, and improves conductivity, thereby increasing weight energy density and volume energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a conventional metal current collector is used, then good conductivity and mechanical strength are achieved, but weight energy density is reduced due to higher weight
Solution Approach 1:
The current collector uses a composite structure consisting of a plastic substrate layer and a metal coating layer. The plastic substrate provides lightweight support while the metal coating layer (Al, Cu, or Ni) provides conductivity and mechanical strength. This composite approach reduces overall weight while maintaining necessary mechanical and electrical properties.
Solution Approach 2:
The metal coating is applied only on the surfaces of the plastic substrate where conductivity and strength are needed, rather than using solid metal throughout. The coating thickness is optimized to provide sufficient electrical conductivity and mechanical reinforcement while minimizing added weight.
2Weight of moving object
If the current collector is made thinner to reduce weight, then weight energy density improves, but mechanical stability deteriorates
Solution Approach 1:
The plastic substrate can be made very thin while maintaining structural integrity because it is reinforced with the metal coating layer. The composite structure provides higher strength-to-weight ratio than conventional solid metal collectors, allowing thinner designs that reduce weight without sacrificing mechanical stability.
Solution Approach 2:
The plastic substrate acts as a flexible thin film that provides the necessary mechanical support at minimal thickness. The thin plastic layer combined with the metal coating achieves the required mechanical stability while keeping the overall weight and thickness low for high energy density applications.
3Weight of moving object
If the conductive layer is made thinner to reduce weight, then weight energy density improves, but conductivity and oxidation resistance deteriorate
Solution Approach 1:
The metal coating thickness is optimized to the minimum required level to achieve sufficient electrical conductivity and oxidation resistance. By carefully controlling the coating thickness parameter, the design achieves adequate performance with minimal weight addition. The plastic substrate thickness is also optimized to balance mechanical support with overall weight reduction.
Data Source
AI summary
A current collector, an electrode plate, and an electrochemical device are provided in the present disclosure. The current collector includes an insulation layer and at least one conductive layer. The insulation layer is used to support the conductive layer. The at least one conductive layer is used to support an electrode active material layer and is located above at least one surface of the insulation layer. The insulation layer has a density smaller than that of the conductive layer. A metal protective layer is arranged on at least one surface of each of the at least one conductive layer.