Stacking-Folding Battery Cells with Bicells for Stability

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Solution Overview

Problem

Existing secondary batteries face challenges in increasing capacity and structural stability, particularly in prismatic and pouch-shaped designs, due to complex manufacturing processes and susceptibility to external impacts and vibrations.

Innovation Solution

The use of stacking-folding type cells with bicells and full cells, where electrodes of the same or different polarities are connected via a long separator sheet, allowing for increased electrical and physical coupling between cells, improving stability and capacity through a simpler assembly process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If stacking type electrode assembly is used to achieve prismatic structure, then spatial utilizability is improved, but manufacturing complexity increases and structural stability deteriorates under external impacts

Engineering Contradiction:

Improvespatial utilizabilityVSAvoidmanufacturing process complexity

Core Design Contradiction:

Volume of moving objectVSDevice complexity

Solution Approach 1:

The electrode assembly is divided into multiple unit cells (first unit cell, second unit cell, etc.), each containing a folded electrode assembly with cathode and anode. This segmentation allows the complex prismatic structure to be built from simpler, standardized modules, reducing overall manufacturing complexity while maintaining high spatial utilizability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple unit cells are stacked and nested within a single battery case, with each unit cell containing folded electrode assemblies nested within separators. This nesting approach achieves high spatial utilizability and integration density while simplifying the external structure and manufacturing process.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Volume of moving object

If stacking type electrode assembly is used to achieve prismatic structure, then spatial utilizability is improved, but structural stability worsens under external impacts

Engineering Contradiction:

Improvespatial utilizabilityVSAvoidstructural stability

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

Separators are disposed between adjacent unit cells before assembly, providing protective cushioning that prevents direct contact and potential short circuits between cells during external impacts or vibrations. This prior protection measure maintains structural stability while preserving the compact stacked design.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

Multiple unit cells are merged into a single integrated battery assembly with unified casing and coordinated electrode connections. This merging approach distributes mechanical stress across the entire structure, improving overall structural stability while maintaining high spatial utilizability.

Inventive Principle:

Principle #5Merging (Combining)

3Quantity of substance

If multiple unit cells are connected to increase battery capacity, then energy storage capacity is improved, but structural stability deteriorates due to loose connections

Engineering Contradiction:

Improvebattery capacityVSAvoidstructural stability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

Multiple unit cells are merged into a tightly integrated stacked assembly where cells are closely positioned and electrically connected through coordinated terminals. This merging ensures stable mechanical and electrical connections while increasing overall battery capacity, preventing the loose connection problems of separate cell arrangements.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Electrode terminals of adjacent unit cells are connected in a manner that maintains equipotential relationships, with cathode terminals connected to cathode terminals and anode terminals to anode terminals. This equipotential connection method ensures both electrical functionality and structural stability when scaling up battery capacity.

Inventive Principle:

Principle #12Equipotentiality

Data Source

PatentUS9343714B2High capacity battery cell employed with two or more unit cells

Publication Date: 2016.05.17 LG ENERGY SOLUTION LTD

AI summary

Disclosed herein is a secondary battery including two or more stacking-folding type cells (‘unit cells’) manufactured by winding small-sized electrode assemblies (‘bicells’) constructed in a stacking type structure in which electrodes having the same polarity are located at opposite sides of each electrode assembly and small sized electrode assemblies (‘full cells’) constructed in a stacking type structure in which electrodes having different polarities are located at opposite sides of each electrode assembly using a long separator sheet, wherein the unit cells are mounted in a battery case, each unit cell has one or more electrode terminals protruding from each end of each unit cell, and the unit cells are mounted in a receiving part of the battery case such that the unit cells are arranged in a stacking arrangement structure or a plane arrangement structure while the electrode terminals of the unit cells are connected with each other.