Solid-State Battery Over-Discharge for Short-Circuit Screening

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional solid-state battery manufacturing methods are inefficient in quickly identifying and preventing the release of defective products due to short-circuiting, which can occur when a metal component reacts with sulfur in the sulfide electrolyte layer, leading to battery degradation and performance deterioration during prolonged high-temperature aging processes.

Innovation Solution

The method involves over-discharging the solid-state battery by applying a voltage of less than −0.5 V in a controlled temperature range of 25° C to 150° C, specifically 60° C to 85° C, to accelerate the diffusion of sulfide components and detect short-circuiting before shipping, thereby reducing battery deterioration and identifying defective products quickly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional heating processing over a long time is used to confirm short-circuiting, then the presence of sulfide formation can be detected, but the process takes too long and defective products cannot be quickly identified before shipping

Engineering Contradiction:
Improvedetection accuracy of short-circuitingVSAvoidtime required for aging process
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the detection parameter from thermal aging (heating over long time) to electrochemical over-discharging. By applying a constant current to over-discharge the battery, the detection method transitions from time-dependent thermal processes to current-dependent electrochemical reactions, enabling rapid detection of short-circuiting within minutes rather than hours or days.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical/thermal aging system with an electrochemical over-discharging system. Instead of using heat and time to accelerate sulfide formation and detection, the invention uses controlled over-discharge currents to directly trigger and detect short-circuit conditions, substituting thermal-mechanical processes with electrical processes that are faster and more direct.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If prolonged high-temperature aging is applied to detect short-circuiting, then defective products can be identified, but battery deterioration increases and performance deteriorates

Engineering Contradiction:
Improvedetection of short-circuitingVSAvoidbattery performance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent changes the detection parameter from high-temperature thermal aging to controlled electrochemical over-discharging. This parameter change allows detection of short-circuiting through electrical behavior rather than thermal acceleration, significantly reducing the energy input and thermal stress applied to the battery, thereby preserving battery performance while maintaining detection reliability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the potential harm of over-discharging (which could damage batteries) into a beneficial detection mechanism. By carefully controlling the over-discharge process, the invention uses the over-discharge condition itself as a diagnostic tool - the controlled stress reveals hidden defects (short-circuiting) without causing permanent damage, turning a potentially harmful process into a quality assurance benefit.

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

3Reliability

If conventional aging processes are used, then short-circuiting can be detected, but the process complexity and manufacturing time increase

Engineering Contradiction:
Improvedefective product identificationVSAvoidmanufacturing speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the detection parameter from time-intensive thermal aging to rapid electrochemical over-discharging. This parameter transformation reduces the detection process from hours or days to minutes, directly improving manufacturing throughput and productivity while maintaining the reliability of defective product identification.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs the detection action (over-discharging) immediately after battery assembly, before shipping and final quality checks. This preliminary detection action identifies potential short-circuiting defects early in the manufacturing process, preventing defective products from progressing further and enabling immediate corrective action, thereby improving overall manufacturing efficiency.

Inventive Principle:
Principle #10Preliminary action

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 approach allows for the rapid confirmation of short-circuiting and prevention of defective product release, reducing battery deterioration and ensuring the quality of solid-state batteries by diffusing foreign metals in a controlled manner, thus preventing short-circuiting and maintaining battery performance.

Implementation Method 1

over-discharging the solid-state battery... to accelerate the diffusion of sulfide components and detect short-circuiting

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentUS20240170638A1Solid-state battery and method of manufacturing solid-state battery
Publication Date: 2024.05.23 TOYOTA JIDOSHA KK

AI summary

A method of manufacturing a solid-state battery, the method including: over-discharging the solid-state battery having a solid sulfide electrolyte layer.