Polycrystalline Lithium Manganese Oxide Particles for Battery Stability
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Solution Overview
Problem
Lithium manganese oxide batteries face limitations such as capacity fading due to Jahn-Teller distortion and manganese dissolution, which affect their cycle and high-temperature characteristics.
Innovation Solution
Polycrystalline lithium manganese oxide particles with a specific chemical formula, Li(1+x)Mn(2−x−y−f)Al(y)MfO(4−z), are synthesized using a dry method with a sintering aid to stabilize the structure and minimize non-uniform reactions, improving crystal growth at low temperatures and reducing manganese dissolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium manganese oxide with spinel crystal structure is used as cathode active material, then thermal stability and cost are improved, but capacity and cycle characteristics deteriorate
Solution Approach 1:
The patent modifies the chemical composition parameters of lithium manganese oxide by controlling the Li/Mn ratio to exceed stoichiometric ratio (Li/Mn > 1) and adjusting doping element concentrations. This parameter change stabilizes the spinel structure during cycling, preventing Jahn-Teller distortion and maintaining both thermal stability and improved cycle characteristics simultaneously
Solution Approach 2:
The patent creates a composite cathode material by doping lithium manganese oxide with transition metals (Ni, Co, Mn) and/or divalent/trivalent cations (Mg, Zn, Al, Ga). This composite approach combines the thermal stability of spinel LiMn2O4 with the structural stability provided by dopant elements, resolving the contradiction between thermal stability and cycle life
2Stability of the object's composition
If excessive Li is added to prevent site exchange between Li and Mn ions, then structural stability is improved, but capacity fading is reduced only partially
Solution Approach 1:
The patent optimizes the Li content parameter to exceed stoichiometric amount (Li > Mn) and controls doping element parameters within specific ranges. This dual parameter optimization achieves complete prevention of Li-Mn site exchange and suppresses both Jahn-Teller distortion and Mn dissolution, fully resolving capacity fading while maintaining structural stability
Solution Approach 2:
The patent combines excessive Li addition with multi-element doping (transition metals and/or divalent/trivalent cations) to create a composite structure. The dopant elements occupy Mn sites and stabilize the oxidation state, working synergistically with excess Li to prevent site exchange and suppress capacity fading mechanisms
3Stability of the object's composition
If Mn sites are substituted with transition metals or divalent and trivalent cations to control oxidation number, then phase transition is prevented, but capacity fading is reduced only partially
Solution Approach 1:
The patent precisely controls the doping concentration parameters within specific ranges (0.01 ≤ x ≤ 0.20 for transition metals, 0.01 ≤ y ≤ 0.20 for divalent/trivalent cations) combined with Li excess parameter (0.05 ≤ δ ≤ 0.20). This multi-parameter optimization simultaneously prevents phase transition and suppresses Mn dissolution, achieving complete capacity retention
Solution Approach 2:
The patent creates a multi-component composite material by combining Li-excess lithium manganese oxide with transition metal dopants and/or divalent/trivalent cation dopants. This composite structure provides dual functionality: phase stability from dopant-induced structural modification and capacity retention from suppressed Mn dissolution through optimized composition
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 enhances the life and charge/discharge capacity characteristics of lithium secondary batteries by stabilizing the structure and reducing manganese dissolution, leading to improved battery performance and stability.
Implementation Method 1
a method of preparing the polycrystalline lithium manganese oxide particles, in which secondary battery characteristics better than those of lithium manganese oxide prepared by a wet method may not only be obtained by a dry method with low production costs, but also crystals may be easily grown at low temperature
Data Source
AI summary
Provided are polycrystalline lithium manganese oxide particles represented by Chemical Formula 1 and a method of preparing the same:Li(1+x)Mn(2−x−y−f)AlyMfO(4−z) <Chemical Formula 1>where M is any one selected from the group consisting of boron (B), cobalt (Co), vanadium (V), lanthanum (La), titanium (Ti), nickel (Ni), zirconium (Zr), yttrium (Y), and gallium (Ga), or two or more elements thereof, 0≤x≤0.2, 0<y≤0.2, 0<f≤0.2, and 0≤z≤0.2.According to an embodiment of the present invention, limitations, such as the Jahn-Teller distortion and the dissolution of Mn2+, may be addressed by structurally stabilizing the polycrystalline lithium manganese oxide particles. Thus, life characteristics and charge and discharge capacity characteristics of a secondary battery may be improved.