Biwedge Octahedron Cathode Particles for Li-Ion Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium-ion battery cathode materials, such as layered composite oxides, face limitations in energy density and discharge power due to their microstructure, particularly in lithium ion migration pathways, necessitating improvements for enhanced performance.
Innovation Solution
A Ni—Mn composite oxalate powder with biwedge octahedron particles is calcined with a lithium salt to form a lithium transition metal composite oxide powder, which features a biwedge octahedron structure and surface trenches, optimizing lithium ion diffusion pathways and increasing the solid/electrolyte contact area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional layered composite oxide cathode materials are used, then high energy density is achieved, but lithium ion migration pathways are limited and discharge power is insufficient
Solution Approach 1:
The cathode material particles are segmented into micro-sized particles with controlled morphology rather than using bulk materials. This segmentation creates multiple lithium ion migration pathways and reduces diffusion distances, thereby improving discharge power while maintaining energy density through optimized particle architecture.
Solution Approach 2:
The invention introduces a new morphological dimension by creating biwedge octahedron particles with specific crystal orientation. This dimensional control of particle shape optimizes the exposure of specific crystal planes that facilitate lithium ion migration, resolving the contradiction between energy density and ion migration speed.
2Ease of manufacture
If conventional cathode material microstructure is used, then material synthesis is simplified, but discharge power and lithium ion diffusion are limited
Solution Approach 1:
The invention changes critical parameters including particle size (micro-sized), particle shape (biwedge octahedron), and crystal orientation to optimize discharge power. These parameter changes are achieved through controlled synthesis conditions that balance manufacturing feasibility with performance enhancement, maintaining ease of manufacture while dramatically improving discharge power.
3Ease of manufacture
If standard particle morphology is used, then manufacturing process is straightforward, but solid/electrolyte contact area is insufficient
Solution Approach 1:
The invention employs asymmetric biwedge octahedron particle morphology instead of conventional symmetric spherical or cubic particles. This asymmetric shape increases the specific surface area and creates more active sites for solid/electrolyte contact, thereby improving discharge power without significantly complicating the manufacturing process through established precipitation methods.
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 resulting lithium-ion battery exhibits improved first cycle discharge capacity and large-current discharge ability, attributed to the biwedge octahedron structure and increased contact area, leading to enhanced electrochemical performance.
Implementation Method 1
A Ni—Mn composite oxalate powder with biwedge octahedron particles is calcined with a lithium salt to form a lithium transition metal composite oxide powder
Implementation Method 2
calcined with a lithium salt to form a lithium transition metal composite oxide powder
Data Source
AI summary
A Ni—Mn composite oxalate powder is provided. The Ni—Mn composite oxalate powder includes a plurality of biwedge octahedron particles represented by the general formula: NiqMnxCoyMzC2O4.nH2O, wherein q+x+y+z=1, 0<q, x<1, 0≦y<1, 0≦z<0.15, 0≦n≦5, and M is at least one of Mg, Sr, Ba, Cd, Zn, Al, Ga, B, Zr, Ti, Ca, Ce, Y, Nb, Cr, Fe and V. The above powder may be further calcined with a lithium salt to form a lithium transition metal oxide powder for use as a positive electrode material in lithium ion-batteries.