Lithium-Ion Cell Sacrificial Electrode for Zero-Voltage Recovery

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Metal ion battery cells, such as lithium ion batteries, are susceptible to internal morphological deformations during charging and discharging, leading to capacity loss and safety hazards like thermal runaway, fires, and explosions due to dendrite formation, especially when discharged to low-voltage or zero-voltage states, for which existing countermeasures like pre-lithiation are not economically viable or effective.

Innovation Solution

Incorporating non-lithium sacrificial electrodes with a lower decomposition voltage than the negative current collector, which decompose instead of the current collector and solid electrolyte interphase, thereby preserving the battery's structural integrity and preventing dendrite formation, even when the battery is in a low-voltage or zero-voltage state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the battery is discharged to low-voltage or zero-voltage states, then the energy density and current output are improved, but internal morphological deformations and dendrite formation occur leading to safety hazards

Engineering Contradiction:

Improveenergy densityVSAvoidsafety

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies preliminary action by incorporating a sacrificial electrode made of non-lithium metal (such as zinc, aluminum, or magnesium) into the battery cell before operation. This sacrificial electrode has a lower decomposition voltage than the negative current collector, so it decomposes first during low-voltage or zero-voltage discharge, preventing dendrite formation and internal short circuits before they can occur. The sacrificial electrode acts as a preemptive protective measure that sacrifices itself to protect the main battery structure.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If pre-lithiation is used to counteract low-voltage instability, then the capacity loss is reduced, but the manufacturing cost increases significantly

Engineering Contradiction:

Improvecapacity stabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs the principle of using cheap, short-living sacrificial electrodes made from non-lithium metals like zinc, aluminum, or magnesium. These materials are significantly less expensive than lithium and can be obtained from common metal foils. The sacrificial electrode is designed to be consumed during low-voltage exposure, serving as a disposable protective element that prevents damage to the main battery components without requiring expensive pre-lithiation processes.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If the negative current collector decomposes during low-voltage exposure, then the electrical connection is maintained, but the structural integrity and cycle life are compromised

Engineering Contradiction:

Improveelectrical connectionVSAvoidcycle life

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent uses an intermediary approach by introducing a sacrificial electrode as a mediator between the negative current collector and the low-voltage environment. The sacrificial electrode, made of non-lithium metal with lower decomposition voltage, acts as a buffer that decomposes instead of the current collector. This intermediary layer protects the structural integrity of the battery while maintaining electrical connectivity through the external circuit during low-voltage or zero-voltage exposure.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

The use of non-lithium sacrificial electrodes enhances the stability and safety of metal ion battery cells by preventing structural degradation and maintaining capacity and cycle life during prolonged low-voltage or zero-voltage exposure, reducing the risk of fires and explosions during storage and transportation.

Implementation Method 1

the non-lithium sacrificial material may have a lower decomposition voltage than the metal foil comprising the negative current collector

Methodology Applied

Scientific EffectElectrochemical decomposition: Electrolysis

Implementation Method 2

welding the negative tab to the disk and the case to provide (i) an electrical connection between the negative electrode and the non-lithium sacrificial material, and (ii) an electrical connection between the negative electrode and a negative terminal of the battery cell

Methodology Applied

Scientific EffectWelding: Welding

Data Source

PatentUS20250006942A1Lithium ion battery with zero voltage recovery function and methods for producing the same

Publication Date: 2025.01.02 AMERICAN LITHIUM ENERGY CORP

AI summary

A method for producing a battery cell may include forming a positive electrode and a negative electrode before interposing a separator therebetween. A disk of a non-lithium sacrificial material, such as zinc (Zn), may be secured to a case. A sheet of materials including the separator interposed between the positive electrode and the negative electrode may be inserted into the case, either wound into a jellyroll or left as is. In some cases, a negative tab extending from the negative electrode may be extended through an opening in the disk of non-lithium sacrificial material. The negative tab may then be welded to the disk and the case of the battery cell to provide an electrical connection between the negative electrode and the non-lithium sacrificial material as well as an electrical connection between the negative electrode and a negative terminal of the battery cell.