Lithium Ferric Phosphate Synthesis via Oxalic Acid Chelation

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Solution Overview

Problem

Conventional methods for preparing Lithium Ferric Phosphate (LFP) composite batteries are costly due to high raw material prices, sensitive to pH values, prone to pipe blockages, and have unstable temperature control, leading to increased operational difficulties and reduced product quality.

Innovation Solution

A preparation method involving phosphoric acid, iron powder, a carbon source, and lithium reactants, with controlled temperature reactions and calcination steps to produce a precursor (Fe7(PO4)6) that reduces material waste and enhances product quality, stabilizes processing conditions, and lowers costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional preparation method using lithium hydroxide and ferric phosphate is applied, then LFP-NCO battery can be produced, but material cost increases significantly

Engineering Contradiction:
Improveproduct qualityVSAvoidmaterial cost
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the chemical parameters of the reaction system by replacing lithium hydroxide with lithium carbonate and using oxalic acid as a chelating agent, which fundamentally alters the reaction pathway and reduces material costs while maintaining product quality

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs inexpensive raw materials such as lithium carbonate, ferric phosphate, and oxalic acid that can be readily consumed in the reaction process, replacing expensive specialty chemicals while achieving the same functional outcome

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Reliability

If acid-base neutralization reactions are used in preparation process, then LFP-NCO battery can be synthesized, but pH sensitivity causes viscosity increase and pipe blockage

Engineering Contradiction:
Improveproduct qualityVSAvoidprocess stability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent extracts and eliminates the acid-base neutralization step from the preparation process by using a different chemical pathway that involves chelation and decomposition reactions instead, thereby removing the source of pH sensitivity and viscosity problems

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces oxalic acid as an intermediary chelating agent that mediates between the metal ions and phosphate, forming stable complexes that prevent unwanted side reactions and maintain process stability throughout the synthesis

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If conventional preparation method with multiple material movements is applied, then LFP-NCO battery can be produced, but pollution risk increases and product quality decreases

Engineering Contradiction:
Improveproduct qualityVSAvoidpollution risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent merges multiple separate preparation steps into a single integrated reaction process where all raw materials are combined and reacted in one vessel, eliminating the need for intermediate transfers and reducing pollution risk from material movements

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent performs preliminary chelation of metal ions with oxalic acid before adding phosphate sources, which pre-organizes the reaction components and ensures complete reactions in a single step, eliminating the need for subsequent material handling and reducing pollution opportunities

Inventive Principle:
Principle #10Preliminary action

4Reliability

If conventional preparation method with multiple grinding times is applied, then LFP-NCO battery can be produced, but processing time and cost increase

Engineering Contradiction:
Improveproduct qualityVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary chelation of metal ions with oxalic acid before adding phosphate sources, which pre-organizes the reaction components and ensures complete reactions in a single step, eliminating the need for subsequent material handling and reducing pollution opportunities

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent maintains continuous reaction conditions throughout the synthesis process by controlling temperature and pH to prevent precipitation and ensure complete reactions, eliminating the need for intermittent grinding and processing steps

Inventive Principle:
Principle #20Continuity of useful 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 method reduces material costs, stabilizes processing temperatures, minimizes pipe blockages, and improves product quality by using fully reacted phosphoric acid and iron powder in two-stage reactions, resulting in a more efficient and cost-effective production process for LFP composite batteries.

Implementation Method 1

allowing deionized water to dissolve a first quantity of the phosphoric acid for forming a first phosphoric acid solution; processing a reaction of the first phosphoric acid solution and the iron powder

Methodology Applied
Scientific EffectOxidation-reduction reaction: Redox Reactions

Implementation Method 2

calcining the first product to produce a precursor; processing a reaction of the precursor, a third quantity of carbon source and the first reactant to get a reaction mixture and calcining the reaction mixture to produce the battery composite material

Methodology Applied
Scientific EffectThermal decomposition: Pyrolysis

Data Source

PatentEP2736101B1Method for preparing battery composite material
Publication Date: 2020.01.22 ADVANCED LITHIUM ELECTROCHEMISTRY CO LTD
  • EP2736101B1 patent drawingFigure 1
  • EP2736101B1 patent drawingFigure 2
  • EP2736101B1 patent drawingFigure 3

AI summary

A preparation method of a battery composite material includes steps of providing phosphoric acid, iron powder, a carbon source and a first reactant, processing a reaction of the phosphoric acid and the iron powder to produce a first product, calcining the first product to produce a precursor, among which the formula of the precursor is written by Fe7(PO4)6, and processing a reaction of the precursor, the carbon source and the first reactant to get a reaction mixture and calcining the reaction mixture to produce the battery composite material. As a result, the present invention achieves the advantages of reducing grind time of fabricating processes, so that the prime cost, the time cost, and the difficulty of fabricating are reduced.