Annealed Electrode Coatings for High Power Density
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Solution Overview
Problem
Conventional lithium-ion batteries are inadequate for meeting the demands of high power and high energy density required for applications in electric vehicles, stationary energy storage, and smart grids, and lack improved conductivity and cycling performance.
Innovation Solution
The development of modified electrode compositions for batteries, including a base composition with active materials like LiMn1.5Ni0.5O4 and LiMn1.5-bNi0.5-cMdO4, which are annealed in a reducing atmosphere to enhance capacity and conductivity, and the use of mesoporous metal oxide microspheres for the anode, along with nitrogen-doped carbon coatings to improve rate capability and cycling performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional lithium-ion battery materials are used, then the battery structure is simple and manufacturing is easy, but the power density and energy density are insufficient for high-performance applications
Solution Approach 1:
The patent employs composite electrode structures combining spinel LiMn1.5Ni0.5O4 particles with carbon coating and surface modification layers. This composite approach achieves high power density (120 mAh/g at 10C rate) while managing the complexity through a systematic multi-layer design that addresses conductivity, stability, and capacity simultaneously
Solution Approach 2:
The patent applies different properties to different regions of the electrode material. The core spinel structure provides high capacity, the carbon coating provides conductivity and stability, and surface modifications provide targeted chemical stability. This local differentiation resolves the contradiction by optimizing each region for its specific function
2Productivity
If conventional electrode materials are used, then the manufacturing process is simple, but the rate capability and cycling performance are inadequate
Solution Approach 1:
The patent modifies key parameters of the electrode material including nickel content (0.4-0.6), carbon coating thickness (1-10 nm), and surface treatment conditions. These parameter optimizations achieve superior rate capability (120 mAh/g at 10C) while maintaining manufacturing feasibility through controlled synthesis processes
Solution Approach 2:
The patent incorporates preliminary surface modification and carbon coating during the synthesis process itself, rather than as separate post-processing steps. This preliminary action integrates multiple functions into the manufacturing process, improving rate capability while minimizing additional manufacturing complexity
3Quantity of substance
If high-capacity materials are used, then the energy density increases, but the conductivity and cycling stability deteriorate
Solution Approach 1:
The patent introduces carbon coating and surface-modified layers as intermediary structures between the high-capacity spinel core and the electrolyte. These intermediaries maintain the high capacity (120 mAh/g at 10C) while providing the conductivity and stability needed for reliable cycling performance through 100+ cycles
Solution Approach 2:
The patent creates a composite structure where the spinel core provides high capacity and the carbon-rich surface layers provide conductivity and stability. This composite approach resolves the contradiction by combining materials with complementary properties to achieve both high capacity and reliable cycling
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 modified electrodes exhibit a capacity at least 125% greater at various discharge rates compared to unmodified electrodes, with the ability to charge quickly and maintain functional discharge capacity of at least 90% after 100 cycles, suitable for grid storage, vehicle, and portable applications.
Implementation Method 1
an annealed composition covering a portion of the base composition, formed by a reaction of the base composition in a reducing atmosphere
Implementation Method 2
formed by a reaction of the base composition in a reducing atmosphere
Implementation Method 3
an active material capable of intercalating the metal ions during a discharge cycle and deintercalating the metal ions during a charge cycle
Implementation Method 4
nitrogen-doped carbon coatings to improve rate capability and cycling performance
Data Source
AI summary
Compositions and methods of making are provided for surface modified electrodes and batteries comprising the same. The compositions may comprise a base composition having an active material capable of intercalating the metal ions during a discharge cycle and deintercalating the metal ions during a charge cycle, wherein the active material is selected from the group consisting of LiCoO2, LiMn2O4, Li2MnO3, LiNiO2, LiMn1.5Ni0.5O4, LiFePO4, Li2FePO4F, Li3CoNiMnO6, Li(LiaNixMnyCoz)O2, LiaMn1.5-bNi0.5-cMdO4-x, and mixtures thereof. The compositions may also comprise an annealed composition covering a portion of the base composition, formed by a reaction of the base composition in a reducing atmosphere. The methods of making comprise providing the base composition and annealing the base electrode in a reducing atmosphere.