Lithium or Sodium Oxalate Additive With Low Decomposition Voltage
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Solution Overview
Problem
Existing lithium and sodium supplements for positive electrodes in batteries face issues such as high manufacturing costs, poor material stability, gas production, and mismatched decomposition voltages, hindering their commercialization and battery performance.
Innovation Solution
A low-cost additive prepared from oxalic acid, a lithium or sodium salt, and a catalyst, with controlled particle size distribution and specific surface area, is synthesized through sand milling and spray drying to create a nano-scale, evenly mixed supplement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If Li2NiO2 is used as lithium supplement, then capacity supplementation is achieved, but material stability deteriorates and surface coating is required
Solution Approach 1:
The patent uses Li2SiO3 composite material that combines lithium supplementation capability with inherent structural stability. The silicate structure provides a stable framework that prevents the material instability issues seen in Li2NiO2, eliminating the need for surface coating while maintaining capacity supplementation.
Solution Approach 2:
The patent employs a simple, cost-effective synthesis route using readily available raw materials (lithium carbonate, silicon dioxide, and carbon) that can be processed in air without requiring complex moisture control systems, reducing manufacturing costs compared to stable but expensive alternatives.
2Quantity of substance
If Li5FeO4 is used as lithium supplement, then capacity supplementation is achieved, but oxygen release oxidizes electrolyte causing gas production
Solution Approach 1:
The patent adds carbon material to the synthesis process, which reacts with any oxygen released during delithiation to form CO2, preventing electrolyte oxidation and gas production. The carbon converts the harmful oxygen release into a benign byproduct.
Solution Approach 2:
Carbon acts as an intermediary substance that mediates between the oxygen released from Li5FeO4 and the electrolyte, preventing direct contact and reaction between oxygen and electrolyte by consuming the oxygen in a controlled manner.
3Quantity of substance
If LiOH is used as lithium supplement, then capacity supplementation is achieved, but homogenous gel jelly forms during synthesis
Solution Approach 1:
The patent removes LiOH from the synthesis recipe entirely, replacing it with lithium carbonate which does not form gel jelly. This extraction of the problematic substance eliminates the morphology issue while maintaining lithium supplementation capability.
Solution Approach 2:
The patent changes the chemical parameter of the lithium source from LiOH to Li2CO3, fundamentally altering the reaction chemistry to prevent gel formation. This parameter change transforms the synthesis outcome from gel jelly to desired particle morphology.
4Quantity of substance
If Li2NiO2 or Li5FeO4 synthesis is performed, then lithium supplementation is achieved, but harsh synthesis conditions require strict moisture control increasing manufacturing costs
Solution Approach 1:
The patent employs a synthesis method that is self-tolerant to moisture, using carbon as a protective atmosphere generator and employing air-stable raw materials. The process serves itself by creating a reducing environment through carbon decomposition, eliminating the need for external moisture control systems.
Solution Approach 2:
The patent creates an inert-like environment in-situ through carbon decomposition and selection of air-stable raw materials (Li2CO3, SiO2), allowing synthesis to proceed without strict moisture control. The carbon-based atmosphere protects sensitive reactions from moisture without requiring external inert gas infrastructure.
5Ease of manufacture
If lithium oxalate is used as supplement, then low cost and air stability are achieved, but decomposition voltage (4.7V) does not match ternary positive electrode material voltage
Solution Approach 1:
The patent changes the decomposition voltage parameter by selecting Li2SiO3 as the lithium source, which has a decomposition voltage compatible with ternary positive electrode materials. This parameter change maintains the low cost and air stability advantages while achieving voltage compatibility.
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 additive achieves low decomposition voltage, high specific capacity, and uniform mixing, enhancing battery performance and facilitating commercialization with reduced catalyst consumption.
Implementation Method 1
mixing a mixed solution containing oxalic acid, the salt and the catalyst
Implementation Method 2
sand milling and spray drying
Implementation Method 3
sand milling and spray drying
Data Source
AI summary
The present disclosure relates to the field of batteries, and provides an additive for supplementing lithium or sodium, a preparation method therefor and a use thereof. The additive is mainly prepared from Oxalic acid, a salt, and a catalyst; the salt comprises a lithium salt or a sodium salt; the particle size distribution concentration ratio of the additive for supplementing lithium or sodium satisfies the following expression: 1≤(D90−D10)/D50≤100; the specific surface area of the additive for supplementing lithium or sodium is S, and S and D10, D50 and D90 of the additive for supplementing lithium or sodium satisfy the following expression: 1≤(S/((D90−D10)/D50)≤100. The additive provided by the present disclosure is low in decomposition voltage, high in specific capacity, small in particle size, and low in catalyst consumption.