Current Collector Terminal Slits for Battery Capacity

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Solution Overview

Problem

Existing secondary battery designs with stacked electrode assemblies face challenges in maximizing battery capacity and energy density due to the space occupied by current collector terminals, which limits the effective area for active material layers.

Innovation Solution

A novel current collector terminal structure featuring rectangular-shaped foils with exposed portions and slits that allow for compact arrangement, reducing the space required for terminals and increasing the area for active material layers, thereby enhancing battery capacity and energy density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If conventional current collector terminals are used in stacked electrode assemblies, then the battery structure is simple and easy to manufacture, but the terminals occupy excessive space reducing the effective area for active material layers

Engineering Contradiction:

Improveeffective area for active material layersVSAvoidterminal structure complexity

Core Design Contradiction:

Area of stationary objectVSDevice complexity

Solution Approach 1:

The current collector terminal is divided into multiple functional segments: a base plate portion for structural support, a curved portion for spatial transition, and a plate portion for electrical connection. The plate portion is further segmented into multiple slits that receive individual exposed portions from different electrode sheets, allowing compact arrangement while maintaining simplicity in manufacturing

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The terminal structure employs a nested arrangement where multiple electrode sheet exposed portions are inserted into slits of the same terminal plate portion. This nesting approach allows multiple electrical connections to be integrated into a single terminal component, reducing the overall number of terminals needed and maximizing the effective area for active material layers

Inventive Principle:

Principle #7Nested doll (Nesting)

2Quantity of substance

If larger current collector terminals are used to ensure adequate electrical connection, then electrical conductivity is improved, but the space for active material layers is reduced

Engineering Contradiction:

Improvebattery capacityVSAvoidterminal volume

Core Design Contradiction:

Quantity of substanceVSVolume of stationary object

Solution Approach 1:

The terminal structure transitions from a conventional planar configuration to a three-dimensional form with a curved portion that bends between the base plate and the plate portion. This dimensional change allows the terminal to occupy less space in the battery's planar view while maintaining adequate electrical connection area through the vertically stacked segmented structure

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The terminal employs a thin-film plate portion with multiple slits that can flexibly accommodate multiple exposed portions from different electrode sheets. This thin-film approach minimizes the terminal's volume while ensuring adequate electrical conductivity through the slits that directly receive and connect to the electrode exposed portions

Inventive Principle:

Principle #30Flexible shells and thin films

3Reliability

If multiple separate terminals are used for each electrode sheet connection, then electrical connection reliability is improved, but the number of components and manufacturing complexity increase

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidmanufacturing ease

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Multiple electrical connection functions are merged into a single integrated terminal component. The plate portion with multiple slits simultaneously receives and electrically connects multiple exposed portions from different electrode sheets, eliminating the need for multiple separate terminals while maintaining connection reliability through the direct slit-to-exposed portion interface

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The terminal structure is designed as a universal component that can accommodate multiple different electrode sheet connections through its multiple slits. The base plate portion provides structural support, the curved portion provides spatial transition, and the plate portion with slits provides multiple electrical connection points, making the single terminal structure universally applicable to multiple electrode sheets

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10522871B2Secondary battery and current collector terminal

Publication Date: 2019.12.31 TOYOTA JIDOSHA KK

AI summary

A secondary battery includes a stacked electrode assembly in which a plurality of positive electrode sheets and a plurality of negative electrode sheets are stacked. Current collector terminals include current collector plate portions each extending along a plane orthogonal to exposed portions of the positive electrode sheets and exposed portions of the negative electrode sheets. Each of base plate portions is continuous with the current collector plate portion and extends along one side of the electrode assembly that is orthogonal to one side thereof from which the exposed portions protrude. Each of the current collector plate portions includes a plurality of slits extending from a tip end of the current collector plate portion along a direction orthogonal to the base plate portion, and extending into a curved portion. The exposed portions are inserted in the slits of the current collector terminals.