Portable Tool Battery Pack With Solid-State Cells for Wide Temperature Use

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Solution Overview

Problem

Lithium-ion batteries in portable tools are unreliable in low-temperature environments due to increased internal resistance and in high-temperature environments due to excessive internal pressure, leading to reduced usability and efficiency.

Innovation Solution

The use of all-solid-state batteries with a solid electrolyte instead of a liquid or gel electrolyte, which allows for wider temperature operation, reduced wiring inductance, safer charging, and integration of temperature measurement circuits to manage temperature fluctuations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If lithium-ion batteries with liquid or gel electrolyte are used to achieve high energy storage density, then energy storage capacity per unit weight or volume is improved, but the battery becomes unusable in low-temperature environments due to increased internal resistance and in high-temperature environments due to excessive internal pressure

Engineering Contradiction:
Improveenergy storage densityVSAvoidusability in varying temperature environments
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent changes the physical state of the electrolyte from liquid or gel to solid, fundamentally altering the battery's operational parameters. This solid electrolyte configuration eliminates temperature-dependent issues such as freezing at low temperatures and excessive pressure at high temperatures, while maintaining high energy storage density through advanced solid-state battery chemistry

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structures combining solid electrolyte with positive and negative electrodes, creating a multi-component solid-state battery system. This composite approach enables the battery to achieve both high energy storage density and reliable operation across wide temperature ranges by leveraging the complementary properties of different solid materials

Inventive Principle:
Principle #40Composite materials

2Power

If lithium-ion batteries are used to achieve high output capacity per unit weight or volume, then power density is improved, but the battery requires cooling systems in high-temperature environments to prevent overheating

Engineering Contradiction:
Improveoutput capacity per unit weight or volumeVSAvoidcooling system requirements
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the cooling system from the battery design by using solid electrolyte that inherently prevents overheating. The solid-state chemistry removes the need for external cooling mechanisms, simplifying the overall device structure while maintaining high power output capacity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The solid electrolyte battery exhibits self-regulating thermal properties, where the solid-state chemistry naturally prevents excessive heat generation and internal pressure buildup. This self-service characteristic eliminates the need for active cooling systems while maintaining safe operation at high power outputs

Inventive Principle:
Principle #25Self-service

3Reliability

If all-solid-state batteries are used to expand usable temperature range, then reliability in varying environments is improved, but wiring inductance increases compared to liquid electrolyte batteries

Engineering Contradiction:
Improveusability in varying temperature environmentsVSAvoidwiring inductance
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the electrolyte state to solid, which fundamentally alters the electrical characteristics of the battery. This parameter change enables wide temperature range operation while the solid electrolyte's inherent properties manage wiring inductance effects, allowing reliable operation across diverse environments

Inventive Principle:
Principle #35Parameter changes

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

All-solid-state batteries provide a wider usable temperature range, increased energy storage density, reduced weight and size, improved safety during charging, and enhanced weatherability, enabling efficient operation in varying conditions without the need for cooling systems.

Implementation Method 1

a battery pack containing one or more all-solid-state battery cells

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Data Source

PatentEP4491341A1Battery-powered portable tool
Publication Date: 2025.01.15 MAKITA CORP
  • EP4491341A1 patent drawingFigure 1
  • EP4491341A1 patent drawingFigure 2
  • EP4491341A1 patent drawingFigure 3

AI summary

A battery-powered portable tool (1) includes: a battery pack (174; 174') containing at least one all-solid-state battery cell (12, 14, 16, 18); a tool main body (180) on which and/or inside which the battery pack is mountable and from which the battery pack is demountable; and a plurality of components (73, 75) contained in the battery pack and/or in the tool main body. The plurality of components is disposed in a first layout or physical configuration (FIGS. 11, 13) when the temperature is low and is disposed in a second layout or physical configuration (FIGS. 12, 14) when the temperature is high. The first layout or physical configuration differs from the second layout or physical configuration.