Lithium Secondary Battery Electrode Particles for High Capacity Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium secondary batteries face challenges in increasing energy density and high output performance due to limitations in cathode and anode materials, particularly with nickel-cobalt-manganese compounds and graphite, which suffer from thermal instability, gas generation, and irreversible capacity loss.
Innovation Solution
A lithium secondary battery design incorporating a lithium composite transition metal compound with nickel, cobalt, and manganese, combined with a silicon carbon composite anode material, where the cathode active material includes single or pseudo-single particles with an average particle diameter of 1 μm or more, and the anode active material has a silicon carbon composite with an average particle diameter greater than 1 μm, optimizing particle size distribution to reduce side reactions and enhance electrochemical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If nickel content in cathode active material is increased to increase capacity, then energy density is improved, but thermal stability deteriorates and gas generation increases
Solution Approach 1:
The cathode active material uses a composite structure combining nickel-cobalt-manganese oxide with lithium phosphate. This composite approach allows the nickel component to provide high capacity while the lithium phosphate component suppresses side reactions and improves thermal stability, resolving the contradiction between increasing nickel content for higher capacity and maintaining thermal stability
Solution Approach 2:
The invention optimizes the particle size parameter of the cathode active material to have an average particle diameter of 1 μm or more. This parameter change reduces the specific surface area, thereby suppressing side reactions with the electrolyte and improving thermal stability while maintaining high capacity from nickel-rich composition
2Quantity of substance
If non-carbon-based anode materials (silicon, tin, oxides) are used to increase capacity, then energy density is improved, but irreversible capacity loss increases due to low initial efficiency
Solution Approach 1:
The anode active material uses a composite structure combining silicon, tin, or their oxides with carbon material. The carbon component provides stable lithium insertion/extraction and reduces irreversible capacity loss, while the silicon/tin component provides high capacity, resolving the contradiction between increasing capacity and reducing energy loss
Solution Approach 2:
The invention optimizes the particle size parameter of the anode active material to have an average particle diameter of more than 1 μm. This parameter change reduces the specific surface area, thereby suppressing side reactions with the electrolyte and reducing irreversible capacity loss while maintaining high capacity from non-carbon-based materials
3Reliability
If graphite anode material is used, then initial efficiency is maintained, but capacity per unit mass is limited and energy density cannot be increased
Solution Approach 1:
The anode active material uses a composite structure combining silicon, tin, or their oxides with carbon material. This composite approach allows the carbon component to maintain good initial efficiency while the silicon/tin component provides high capacity per unit mass, resolving the contradiction between maintaining initial efficiency and increasing energy density
4Speed
If particle size is decreased to increase surface area for reactions, then reaction rate is improved, but side reactions with electrolyte increase
Solution Approach 1:
The invention optimizes the particle size parameter to have an average particle diameter of 1 μm or more for cathode and more than 1 μm for anode. This parameter change reduces the specific surface area, thereby suppressing side reactions with the electrolyte while maintaining adequate reaction rate through the intrinsic high reactivity of the composite material structure
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
This configuration increases energy density, improves high output performance, and enhances battery cycle life by minimizing side reactions and diffusion resistance, leading to stable capacity retention and efficiency.
Implementation Method 1
The lithium secondary battery generates electric energy by oxidation and reduction reactions during intercalation and deintercalation of lithium ions
Implementation Method 2
intercalation and deintercalation of lithium ions at a cathode and an anode in a state in which an organic electrolytic solution or polymer electrolytic solution is filled between the cathode and the anode
Data Source
AI summary
A lithium secondary battery includes a cathode having a cathode active material, an anode having an anode active material, a separator, and an electrolyte. The cathode active material comprises a lithium composite transition metal compound having Ni, Co, and Mn, and has single particles and/or pseudo-single particles. Each single particle consists of one nodule, and each pseudo-single crystal is a composite of 30 or fewer nodules. The single particles and/or pseudo-single particles have an average particle diameter (D50) of 1 μm or more.