Lithium-Ion Cell Housing Segmentation for Electrical Contact
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Solution Overview
Problem
Current lithium-ion energy storage elements, particularly cylindrical round cells, face challenges in achieving high energy density while maintaining efficient processing and safety, with issues such as dead volume affecting energy density and reliability concerns regarding overpressure protection.
Innovation Solution
The energy storage element features a sealed housing with a metallic cup-shaped housing and a cover component, including a connection pole made of different metallic materials for easy integration and laser welding, and a housing entirely composed of aluminum for enhanced safety and efficiency, with a contact plate connected to the anode current collector and a separate connection pole for the cathode, allowing for improved thermal management and current carrying capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the housing base is made entirely of aluminum, then weight is reduced and corrosion resistance is improved, but electrical contact with the positive electrode is eliminated (which is actually desirable for safety)
Solution Approach 1:
The housing base is segmented into two functional zones: an aluminum portion for structural support and corrosion resistance, and a copper portion for reliable electrical contact with the positive electrode. This segmentation allows each material to perform its optimal function without compromise.
Solution Approach 2:
Different regions of the housing base are assigned different material properties: the aluminum region provides lightweight structural support and corrosion resistance, while the copper region provides high electrical conductivity for reliable contact with the positive electrode. Each local area has the quality it needs for its specific function.
2Quantity of substance
If dead volume is eliminated from the housing design, then energy density is improved, but manufacturing complexity increases
Solution Approach 1:
The housing base is merged with the electrical contact function by integrating a copper portion directly into the aluminum housing base. This eliminates the need for separate contact components and reduces overall structural complexity while maximizing usable volume.
Solution Approach 2:
The housing base serves multiple functions simultaneously: structural support, corrosion resistance, electrical contact, and thermal management. The copper portion provides both structural and electrical functions, eliminating dead volume while reducing the need for additional components.
3Ease of manufacture
If the connection pole uses a single metallic material, then manufacturing is simplified, but adaptability to different contact materials is reduced
Solution Approach 1:
The connection pole is constructed as a composite structure with a first metallic material (e.g., copper or copper alloy) optimized for electrical conductivity and a second metallic material (e.g., aluminum or aluminum alloy) optimized for weight and corrosion resistance. This composite structure provides both manufacturing efficiency and adaptability to different contact requirements.
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 design enhances energy density, facilitates easier integration into cell assemblies, and provides improved safety through reliable overpressure protection and efficient thermal management, addressing the limitations of existing cylindrical round cells.
Implementation Method 1
a contact plate (111) which sits on the first edge (106a) of the anode current collector (106) and is connected to it by welding
Implementation Method 2
The cover component (102) is arranged in the circular opening of the cup-shaped housing part (101) in such a way that its edge lies against the inside of the cup-shaped housing part (101) along a circumferential contact zone, the edge of the cover component (102) being connected to the cup-shaped housing part (101) via a circumferential weld seam (118)
Implementation Method 3
Electrochemical energy storage elements are capable of converting stored chemical energy into electrical energy through a redox reaction
Implementation Method 4
The second part (102f) is preferably pressed into the cup-shaped part (102e) or fixed in the cup-shaped part (102e) by means of a screw connection. An additional fixation by welding is possible
Data Source
Figure 1~1(B)
Figure 2
Figure 3
AI summary
An energy storage element (100) comprises an airtight and liquid-tight sealed housing and an electrode-separator assembly (104) arranged therein.The electrode-separator assembly (104) comprises an anode (105) with an anode current collector (106) and a cathode (108) with a cathode current collector (109), wherein the anode current collector (106) and the cathode current collector (109) each comprise a main region loaded with a layer of an electrode material (107, 110) and, along a first longitudinal edge (106a, 109a), a free edge strip (106b, 109b) not loaded with the electrode material, and the anode (105) and the cathode (108) are arranged such that the first edge (106a) of the anode current collector (106) consists of a first flat terminal end face (104a) and the first edge (109a) of the cathode current collector (109) consists of exit a second flat terminal end face (104b) of the electrode-separator assembly (104).The housing comprises a metallic, cup-shaped housing part (101) with a housing base (101a) and an end opening, as well as a cover part (102) with a cover plate (102a) that is welded into and closes the end opening. A terminal pole (102b) passes through an opening in the cover plate (102a) and is electrically insulated from the cover plate (102a). The energy storage element comprises a contact plate (111) that rests on the first edge (106a) of the anode current collector (106) and is welded to it, and which is simultaneously electrically connected to the terminal pole (102b) that passes through the opening in the cover plate (102a).It is proposed that the terminal pole (102b) comprises a first contacting area (102c) made of nickel or copper or titanium or a nickel or copper or titanium alloy or stainless steel and a second contacting area (102d) made of aluminum or an aluminum alloy, wherein the second contacting area (102d) is mechanically contactable from outside the housing.