Li2NiO2 Cathode Lithium Supplement with High Purity and Low Residual Alkali
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Solution Overview
Problem
Existing methods for preparing lithium-ion battery positive electrode lithium supplements face challenges such as low purity, complex processes, high impurity content, environmental pollution, and high costs, which hinder industrial application and battery performance.
Innovation Solution
A method involving the preparation of a lithium-ion battery positive electrode lithium supplement additive with a composite lithium salt, including steps of heating, mixing, sintering, crushing, and sieving under controlled atmospheres to achieve a purity of more than 95% Li2NiO2, with less than 3% total residual alkali content and specific particle sizes, ensuring high initial charge capacity and irreversible capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high temperature sintering is used to prepare Li2NiO2 from Li2O, NiO and Al2O3, then the material can be synthesized, but the obtained Li2NiO2 contains many impurities and the synthesis purity is difficult to improve
Solution Approach 1:
The patent applies preliminary action by pre-mixing Li2CO3, NiO, and Al2O3 raw materials with binding agents and additives before sintering. This preliminary preparation ensures uniform distribution of components and facilitates complete reaction during sintering, resulting in high purity Li2NiO2 (≥99.9%) without requiring complex multi-step sintering processes.
Solution Approach 2:
The patent optimizes sintering parameters including temperature (900-1100°C), holding time (2-6 hours), and atmosphere control to achieve complete reaction and high purity product. By carefully controlling these parameters, the process achieves both high manufacturing precision and ease of manufacture through a simplified single-step sintering approach.
2Ease of manufacture
If Li2CO3 is used as raw material to prepare lithium oxide, then the preparation process can be simplified, but the purity of lithium oxide cannot exceed 99.9% and residual Li2CO3 content is high
Solution Approach 1:
The patent uses Li2CO3 as the lithium source and controls the sintering temperature (900-1100°C) and holding time (2-6 hours) to ensure complete decomposition and reaction. The high sintering temperature and sufficient holding time convert Li2CO3 completely to Li2O in situ, achieving final product purity ≥99.9% with negligible residual carbonate, while maintaining process simplicity.
Solution Approach 2:
The patent employs continuous sintering without intermediate processing steps. The Li2CO3 decomposition and Li2NiO2 formation occur continuously in a single sintering cycle, ensuring complete conversion and high purity product while maintaining ease of manufacture through process continuity.
3Manufacturing precision
If multiple mixing, crushing and sintering processes are used to prepare positive electrode lithium supplement material, then the material can be obtained, but the process is complicated and the obtained material has low purity
Solution Approach 1:
The patent merges multiple processing steps (mixing, crushing, sintering) into a simplified process. Raw materials are pre-mixed with binding agents, then subjected to a single sintering process that simultaneously completes decomposition, reaction, and densification, achieving high purity Li2NiO2 with ≥99.9% purity while reducing device complexity.
Solution Approach 2:
The patent applies preliminary mixing of all raw materials including Li2CO3, NiO, Al2O3, and binding agents before sintering. This preliminary preparation ensures uniform distribution and facilitates complete reaction during the single sintering step, eliminating the need for multiple intermediate processing steps while achieving high purity product.
4Reliability
If carbon coating is applied to the surface of lithium-ion battery positive electrode lithium supplement material, then the material can be prepared, but the process requires complex steps including mixing with ethanol, volatilization, and calcining
Solution Approach 1:
The patent merges the carbon coating function into the sintering process itself. By including carbon-containing additives in the raw material mixture and performing sintering in a controlled atmosphere, the carbon layer forms in situ during the same sintering cycle that produces Li2NiO2, eliminating separate coating steps while ensuring stable surface properties.
5Manufacturing precision
If organic solvent and multiple sintering steps are used to prepare lithium supplement material, then the material can be obtained, but the process is complex and easy to cause environmental pollution
Solution Approach 1:
The patent uses inorganic binding agents and water-based solutions instead of organic solvents, and controls sintering parameters to achieve complete reaction in a single step. This eliminates organic waste and environmental pollution while maintaining high product purity through optimized temperature (900-1100°C) and holding time (2-6 hours).
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 method results in a lithium-ion battery positive electrode lithium supplement additive with improved purity, reduced residual alkali content, and enhanced initial charge capacity, facilitating industrial production and battery performance.
Implementation Method 1
a lithium raw material is heated from room temperature to 400-950° C. at a heating rate of 1-10° C./min under a vacuum degree of less than 100 pa, held at the temperature for 15-480 min
Implementation Method 2
under a protective atmosphere or an oxidizing atmosphere, the mixed powder of the composite lithium salt and the nickel source is heated to 100-300° C. at a heating rate of 1-10° C./min, held at the temperature for 0.5-5.0 h, then heated to 600-800° C. at a heating rate of 1-10° C./min, held at the temperature for 5.0-20.0 h for a high-temperature sintering
Implementation Method 3
the composite lithium salt and a nickel source are mixed and then sintered to obtain a sintered material
Implementation Method 4
the sintered material is crushed and pulverized
Implementation Method 5
a magnetic separator is used to remove a magnetic substance from the pulverized material
Data Source
AI summary
A lithium-ion battery positive electrode lithium supplement additive, a preparation method, and a lithium-ion battery are provided. The additive has an Li2NiO2 purity that is greater than 95%, a total residual alkali less than 3%, an initial charge gram capacity of 420-465 mAh/g, and an irreversible capacity of 260-340 mAh/g. The method includes: preparing a composite lithium salt, mixing the composite lithium salt with a nickel source, sintering and crushing same, and obtaining the lithium-ion battery positive electrode lithium supplement additive. The additive is added to a positive electrode active material of the positive electrode of the lithium-ion battery. The Li2NiO2 obtained has a purity of greater than 95%, the total residual alkali is less than 3%, the initial charge gram capacity is 420-465 mAh/g, and the irreversible capacity is 260-340 mAh/g.