Battery Cell Spacer Layout for Electrolyte Leak Isolation

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Solution Overview

Problem

In electric power storage devices, when the outer encasement is damaged, electrolytic solution leakage can lead to unintended electrical connections between anode and cathode tabs, causing short-circuiting due to the flow of electrolyte along the outer peripheral face of stacked batteries.

Innovation Solution

Incorporating spacers between cells that protrude further than the outer encasement, with extending portions to divert and retain leaked electrolyte, preventing it from flowing along the side faces and thus avoiding electrical connections between adjacent cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If cells are stacked closely together to increase energy density, then productivity and space utilization are improved, but the risk of electrolytic solution flowing between adjacent cells increases, causing short-circuiting

Engineering Contradiction:

Improveenergy densityVSAvoidshort-circuit prevention

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

A spacer member is introduced as an intermediary component between adjacent cells. The spacer includes a blocking portion that protrudes into the space between cells to block electrolytic solution flow, and extending portions that guide the electrolytic solution away from the terminal portions, preventing short-circuiting while maintaining close stacking

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The spacer member is segmented into functional portions: a blocking portion for stopping electrolytic solution flow, extending portions for guiding flow away from terminals, and positioning portions for securing the spacer between cells. This segmentation allows each portion to perform its specific function effectively

Inventive Principle:

Principle #1Segmentation

2Reliability

If spacers are added between cells to prevent electrolytic solution flow, then reliability is improved, but device complexity increases due to additional components

Engineering Contradiction:

Improveshort-circuit preventionVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The spacer member performs multiple functions simultaneously: it blocks electrolytic solution flow with its blocking portion, guides electrolytic solution away from terminals with its extending portions, and maintains cell spacing with its positioning portions. This multi-functionality reduces the need for separate components for each function

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If extending portions are designed to retain electrolytic solution, then short-circuiting is prevented, but corrosion of spacers may increase due to electrolyte accumulation

Engineering Contradiction:

Improveelectrical isolationVSAvoidcorrosion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The extending portions utilize the electrolytic solution flow to guide it away from vulnerable terminal portions and toward designated retention areas. The blocking portion strategically directs electrolytic solution flow into the extending portions where it can be contained without causing corrosion to critical components, converting the harmful flow into a controlled pathway

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 effectively suppresses short-circuiting by redirecting and containing the leaked electrolyte, preventing unintended electrical connections and reducing corrosion of spacers.

Implementation Method 1

Each of the first end portion and the second end portion is provided with an extending portion heading to one side in the up-down direction

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Implementation Method 2

When the extending portion heads upward, the electrolytic solution can be retained inside the extending portion

Methodology Applied

Scientific EffectSurface tension: Surface Tension

Data Source

PatentUS20230378590A1Electric power storage device

Publication Date: 2023.11.23 TOYOTA JIDOSHA KK

AI summary

An electric power storage device includes multiple cells, and multiple spacers, each of the spacers being disposed between cells that are adjacent. Each of the cells includes an outer encasement member accommodating an electrolytic solution inside, and a first terminal portion and a second terminal portion. The first terminal portions and the second terminal portions are disposed arrayed alternating in each of a first protruding direction and a second protruding direction, protruding from the outer encasement member as viewed from above. Each of the spacers includes a first end portion that protrudes further outward than an end portion of the outer encasement member in the first protruding direction, and a second end portion that protrudes further outward than the end portion of the outer encasement member in the second protruding direction, and each of the first end portion and the second end portion is provided with an extending portion.