Fluoride Pre-Lithiation Coating for Li-Ion Lithium Loss Compensation

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Solution Overview

Problem

Conventional Li-ion battery cells experience a loss of lithium ions during the formation process, leading to reduced energy density and performance, necessitating additional lithium addition to compensate for this loss.

Innovation Solution

A pre-lithiation layer comprising lithium-containing fluoride or oxyfluoride, metal fluoride, and conductive materials is applied to the cathode or separator, facilitating the release of lithium ions to enhance the initial lithium content within the battery cell, thereby maintaining energy density and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If lithium is added to compensate for lithium loss, then energy density and performance are maintained, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvelithium contentVSAvoidbattery structure complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

A pre-lithiation layer is applied to the cathode before battery assembly and initial charging. This layer contains lithium reservoir materials (such as lithium metal, lithium alloys, or lithium compounds) that release lithium ions during the initial charge cycle to compensate for lithium loss in the anode, eliminating the need for additional lithium addition later in the manufacturing process

Inventive Principle:

Principle #10Preliminary action

2Quantity of substance

If conventional Li-ion battery cells are used, then manufacturing is simpler, but lithium ion loss leads to reduced energy density and performance

Engineering Contradiction:

Improvelithium ion retentionVSAvoidmanufacturing process simplicity

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

A pre-lithiation layer serves as an intermediary component between the cathode and anode, containing lithium reservoir materials that act as a buffer to compensate for lithium ion loss during initial charging cycles. This layer releases lithium ions to replenish what is lost in the anode, maintaining overall lithium balance without requiring complex manufacturing modifications

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention modifies the cathode structure by adding a pre-lithiation layer with specific lithium-containing materials (such as lithium metal, lithium alloys, or lithium compounds) in controlled amounts. This changes the lithium content parameter of the cathode to ensure sufficient lithium availability during initial charging, compensating for expected lithium loss while maintaining manufacturing feasibility

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

The pre-lithiation layer effectively compensates for lithium loss, stabilizes the anode, and enhances the battery's energy density and lifespan by ensuring consistent lithium availability during discharge and charge cycles.

Implementation Method 1

The pre-lithiation layer comprising a lithium-containing fluoride or oxyfluoride, a metal fluoride and/or metal oxyfluoride

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentUS20240332507A1Pre-lithiation with fluorides and dual layer coatings

Publication Date: 2024.10.03 APPLE INC

AI summary

This disclosure relates to battery cells, and more particularly, methods and compositions for pre-lithiation of battery cells.