Lithium Anode Pattern Lamination for High-Capacity EV Batteries
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Solution Overview
Problem
Conventional roll-to-roll lamination techniques for producing lithium-metal anodes are limited by the physical properties of lithium, restricting the width of ultra-thin lithium foil to about 120 mm, which in turn limits the size of lithium-metal electrochemical cells, particularly hindering the development of high-capacity batteries required for applications like electric vehicles.
Innovation Solution
A method of forming anodes with electrical tabs by laminating metal foil as patches on a current-collector web, using conductive coatings to improve adhesion and prevent delamination, allowing for larger anode sizes and higher capacity batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If conventional roll-to-roll lamination is used to laminate ultra-thin lithium foil, then the anode structure is formed, but the width of lithium foil is limited to about 120 mm which restricts anode size
Solution Approach 1:
The lithium foil is applied as multiple discrete patches rather than a continuous sheet. Each patch is laminated separately onto the current collector web, allowing the patches to be spaced apart and enabling the overall anode structure to exceed the width limitations of individual lithium foil pieces. This segmentation approach bypasses the 120 mm width constraint by composing a larger anode from multiple smaller units.
Solution Approach 2:
A conductive coating is applied to the current collector web to serve as an intermediary layer between the lithium patches and the current collector. This conductive coating improves adhesion of the lithium patches, prevents delamination during processing, and enables the handling and assembly of larger anode structures that would otherwise be difficult to manage with conventional continuous foil lamination.
2Quantity of substance
If larger anode sizes are produced, then cell capacity and energy density increase, but conventional lamination techniques cannot achieve the required dimensions
Solution Approach 1:
By dividing the lithium anode into multiple discrete patches spaced along the current collector web, the system can achieve larger overall anode dimensions and higher cell capacity without requiring a single continuous piece of lithium foil exceeding manufacturing capabilities. The segmented approach allows scalable production of large-capacity anodes.
Solution Approach 2:
The invention transitions from a single-dimensional continuous foil approach to a multi-dimensional arrangement where lithium patches are distributed along the length of the current collector web. This dimensional reorganization allows the anode to achieve larger effective area and capacity by utilizing the longitudinal dimension of the web rather than relying solely on width expansion.
3Weight of moving object
If lithium foil is made ultra-thin to increase energy density, then volumetric and gravimetric energy densities improve, but the physical properties of lithium make it difficult to handle and process
Solution Approach 1:
Ultra-thin lithium foil is processed into discrete patches that are individually laminated onto the current collector. This segmentation makes the handling of ultra-thin material more manageable compared to continuous foil, reducing the risks associated with handling extremely thin lithium while maintaining the high energy density benefits of ultra-thin construction.
Solution Approach 2:
The conductive coating on the current collector acts as an intermediary that enhances the adhesion of ultra-thin lithium patches, preventing them from delaminating during processing and assembly. This intermediary layer makes ultra-thin lithium much easier to handle and process by providing mechanical stability without adding significant weight or volume.
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
Enables the production of lithium anodes with dimensions up to 150 mm x 600 mm, resulting in significantly higher cell capacity, energy density, and reduced packaging requirements, suitable for high-energy-demand applications such as electric vehicles.
Implementation Method 1
using conductive coatings to improve adhesion and prevent delamination
Data Source
AI summary
A method of forming anodes for electrochemical devices by laminating a metal foil to a current collector and creating anode-active-material patches, composed of the metal foil, that are spaced from one another by inter-patch regions, wherein each inter-patch region provides a location for forming one or more electrical tabs of the finished anodes. The method can further include applying conductive-coating patches to the current collector prior to laminating the metal foil to the current collector, wherein each conductive-coating patch corresponds to one of the anode-active-material patches. In some embodiments, the conductive-coating patches can assist with forming the anode-active-material patches and/or can improve the cycling performance of an electrochemical device made using anodes made therewith. Anodes containing anode-active material and conductive coatings applied to current collectors are also disclosed.