Boron-Coated Cathode Active Material for Lithium Secondary Battery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium secondary batteries face issues with non-uniform chemical structures due to lithium precipitation, leading to reduced capacity and life-span stability, and existing impurity removal methods can damage the cathode active material's structure during charging and discharging.
Innovation Solution
A method involving the use of a boron compound cleaning solution, such as boric acid, to clean and form a boron coating or doping on lithium metal oxide particles, enhancing surface stability and impurity removal while maintaining high lithium content, thereby improving structural and electrical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If water washing is used to remove lithium salt impurities, then some impurity removal is achieved, but particle surface is damaged and sufficient impurity removal is not implemented
Solution Approach 1:
The patent changes the chemical parameter of the cleaning solution from pure water to a boron compound-containing solution (such as boric acid with 0.1-5 wt%). This parameter change enables effective removal of lithium salt impurities while preventing particle surface damage, as the boron compound forms a protective effect on the surface during cleaning
Solution Approach 2:
The boron compound acts as an intermediary substance between the cleaning process and the lithium metal oxide particles. It mediates the cleaning action by enabling impurity removal through chemical interaction while simultaneously protecting the particle surface from mechanical or chemical damage that would occur with plain water washing
2Quantity of substance
If lithium metal oxide structure is deformed or damaged during repeated charging and discharging, then capacity is increased, but life stability and capacity retention characteristics are deteriorated
Solution Approach 1:
The patent applies preliminary action by performing boron compound cleaning and surface treatment before the lithium metal oxide enters the battery. This preliminary surface modification with boron compounds creates a stable surface layer that prevents structure deformation and damage during subsequent repeated charging and discharging cycles, thereby maintaining life stability
Solution Approach 2:
The boron compound treatment provides beforehand cushioning by creating a protective surface layer on the lithium metal oxide particles before they undergo stress during battery operation. This protective layer cushions against structural deformation and damage that would otherwise occur during repeated charging and discharging, preserving capacity retention characteristics
3Quantity of substance
If non-uniformity of chemical structure occurs due to lithium precipitation, then capacity may be increased, but operational stability is reduced
Solution Approach 1:
The patent changes the chemical composition parameter by introducing boron compounds (0.1-5 wt% boric acid) in the cleaning solution. This parameter change prevents lithium precipitation that would cause non-uniform chemical structure, while maintaining high lithium content and improving operational stability through uniform surface treatment
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 boron coating or doping improves the lithium secondary battery's capacity, power retention, and life-span stability by effectively removing impurities and preventing excessive capacity reduction, while maintaining high lithium content on the surface.
Implementation Method 1
The preliminary lithium metal oxide particle may be cleaned using a boron compound cleaning solution
Implementation Method 2
after the cleaning the preliminary lithium metal oxide particle, drying or thermally treating the preliminary lithium metal oxide particle may be further performed to convert the preliminary lithium metal oxide particle into a lithium metal oxide particle that contains a boron doping or a boron coating
Data Source
AI summary
In a method of manufacturing a cathode active material for a lithium secondary battery, a preliminary lithium metal oxide particle is prepared. The preliminary lithium metal oxide particle is cleaned using a boron compound cleaning solution. A cathode active material for a lithium secondary particle includes a lithium metal oxide particle where a ratio of a B+ peak intensity relative to a sum of peak intensities of Li+, B+ and LiB+ fragments by a TOF-SIMS analysis is in a range from 0.03% to 1.5%.