Cylindrical Energy Storage Cell Layout for Higher Density and Venting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium-ion cells have limitations in energy density and reliability, particularly due to dead volume in cylindrical designs that affect energy efficiency and overpressure protection, which compromises their performance in high-energy applications.
Innovation Solution
The design features an air- and liquid-tight sealed housing with a metallic cup-shaped housing part and a lid component, including a negative terminal that is electrically insulated from the lid plate, and an electrode-separator assembly with flat terminal end faces and free edge strips on current collectors, allowing for improved energy density and enhanced safety through efficient terminal connections and overpressure protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If cylindrical round cell design is used, then high current capability is achieved, but dead volume increases reducing energy density
Solution Approach 1:
The electrode assembly is divided into multiple electrode stacks arranged in parallel within the cylindrical housing. Each stack consists of alternating layers of positive electrodes, negative electrodes, and separators. This segmentation allows efficient space utilization while maintaining high current capability through parallel current paths.
2Reliability
If traditional terminal connection is used, then electrical connection is established, but internal resistance increases reducing energy efficiency
Solution Approach 1:
Multiple current collectors from different electrode stacks are merged and connected to common terminal plates at both ends of the cylindrical cell. This merging of current paths reduces internal resistance by providing parallel conduction paths, improving energy efficiency while maintaining reliable electrical connection.
3Volume of stationary object
If compact housing design is used, then space efficiency is improved, but overpressure protection capability is reduced
Solution Approach 1:
The housing is segmented into a compact cylindrical structure with integrated end plates that serve multiple functions: mechanical closure, electrical terminal mounting, and overpressure relief. This segmentation allows the housing to maintain compact dimensions while incorporating dedicated overpressure protection features.
4Quantity of substance
If electrode material is loaded across entire current collector, then active material quantity is maximized, but manufacturing complexity increases
Solution Approach 1:
The electrode manufacturing process applies active material coating selectively to specific regions of the current collector. The coating density and distribution are optimized locally based on functional requirements, allowing maximum active material quantity while simplifying manufacturing through region-specific processing rather than uniform coating across the entire current collector.
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
This configuration enhances energy storage elements' energy density and safety by reducing internal resistance, improving current-carrying capacity, and providing reliable overpressure protection, making them suitable for high-energy applications like electric vehicles.
Implementation Method 1
Electrochemical energy storage elements can convert stored chemical energy into electrical energy by virtue of a redox-reaction
Implementation Method 2
This ion current crosses the separator and is made possible by an ion-conducting electrolyte
Implementation Method 3
a lid component welded into and closing the terminal opening of the cup-shaped housing part
Data Source
AI summary
An energy storage element includes an air- and liquid-tight housing. The housing includes a metallic, cup-shaped housing part with a housing bottom and a terminal opening. The housing further includes a lid component welded into and closing the terminal opening of the cup-shaped housing part, the lid component including a metallic lid plate and a negative terminal passed through an aperture in the lid plate and electrically insulated from the lid plate. The energy storage element also includes an electrode-separator assembly having a first flat terminal end face, a second flat terminal end face, an anode with an anode current collector having a first edge and a second edge parallel thereto, and a cathode with a cathode current collector having a first edge and a second edge parallel thereto. A contact sheet metal member is seated on the first edge of the anode current collector and connected thereto by welding.