Lithium Battery Positive Active Material Precursor for High Tap Density
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Solution Overview
Problem
Rechargeable lithium batteries face challenges in achieving high tap density, energy density, and electrical conductivity in their positive active materials, which affect their performance and productivity.
Innovation Solution
A positive active material precursor for rechargeable lithium batteries is developed, comprising a metal oxide represented by Chemical Formula [NiaCobMcMnd]3O4 or Li1+x[NiaCobMcMnd]1−xO2−yFy, where M is a transition element, with specific composition and particle characteristics, and prepared through a method involving mixing nickel, cobalt, manganese sources, and lithium under an oxidizing atmosphere followed by heat treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional positive active materials are used, then the battery can operate, but the tap density and energy density are insufficient
Solution Approach 1:
The invention changes the chemical composition parameters by incorporating specific transition elements (Ti, V, Cr, Fe, Cu, Zn, Y, Zr, Nb, Mo, or W) in controlled amounts (0≤c≤0.05) into the spinel structure [NiaCobMcMnd]3O4, and adjusts the lithium content parameter (1.05≤x≤1.3) in the final compound Li1+x[NiaCobMnd]1-xO2-yFy to achieve high tap density while maintaining electrical conductivity
Solution Approach 2:
The invention creates a composite material system by combining multiple metal elements (Ni, Co, Mn, and transition element M) in a spinel structure, then further composite with lithium to form the final Li1+x[NiaCobMnd]1-xO2-yFy compound, achieving both high tap density and electrical conductivity through the synergistic effect of different elements
2Quantity of substance
If the positive active material has high tap density, then the energy density improves, but the manufacturing complexity increases
Solution Approach 1:
The invention performs preliminary action by pre-forming the spinel structure [NiaCobMcMnd]3O4 with the correct stoichiometry and crystal structure before the final lithium incorporation step, ensuring that the high tap density is achieved during the precursor formation rather than requiring complex post-processing to achieve dense packing
Solution Approach 2:
The invention controls the particle morphology parameter by forming spherical particles with specific size distribution during the co-precipitation process, and adjusts the lithium content (1.05≤x≤1.3) to optimize both energy density and manufacturing simplicity through a straightforward heat treatment process
3Productivity
If conventional preparation methods are used, then the process is simple, but the productivity and economy are poor
Solution Approach 1:
The invention segments the manufacturing process into two distinct stages: (1) co-precipitation to form the spinel precursor [NiaCobMcMnd]3O4 with controlled composition, and (2) lithium incorporation through heat treatment to form the final product. This segmentation allows each step to be optimized independently, improving productivity while maintaining ease of manufacture
Solution Approach 2:
The invention changes the chemical parameters during co-precipitation by controlling the pH, temperature, and metal ion ratios to directly form the desired spinel structure with high tap density, eliminating the need for complex sintering or densification steps and thereby improving both productivity and manufacturing simplicity
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 solution results in a positive active material with high tap density, improved energy density, electrical conductivity, and enhanced cycle-life and high-rate capabilities, leading to better battery performance and productivity.
Implementation Method 1
mixing the positive active material precursor and a lithium source followed by heat treatment
Implementation Method 2
mixing at least one of a nickel source, a cobalt source, and a manganese source, and a solvent, under an oxidizing atmosphere to form a positive active material precursor
Data Source
AI summary
Provided are a positive active material precursor for a rechargeable lithium battery including a metal oxide represented by Chemical Formula 1, a positive active material for a rechargeable lithium battery that is obtained by using the positive active material precursor for a rechargeable lithium battery and includes a compound represented by a Chemical Formula 2, and a rechargeable lithium battery including the positive active material for a rechargeable lithium battery.