Cathode Active Material Co-precipitation for Battery Rate Performance
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Solution Overview
Problem
Lithium-ion batteries face limitations in capacity, cycle life, and electrode resistance, particularly in automotive applications, where fast charging and discharging with minimal internal losses are desired without compromising safety or electrochemical performance.
Innovation Solution
A process for producing a particulate material of the formula NiaCobMncMd(O)x(OH)y, where M is Al or Ti, through co-precipitation of nickel, cobalt, and manganese hydroxides, followed by drying in the presence of oxygen, to create a cathode active material with improved rate performance and reduced electrode resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If doping with aluminum or titanium is performed to improve battery safety and cycle life, then safety and cycle life are improved, but overall capacity decreases
Solution Approach 1:
The patent applies local quality by doping aluminum or titanium at specific low concentrations (0.001 to 0.03 mol fraction) within the cathode material structure. This localized doping approach improves safety and cycle life through enhanced structural stability at doped sites without significantly reducing overall capacity, as the majority of the material retains its high-capacity characteristics.
2Speed
If fast charge and discharge at high currents is implemented, then rate performance is improved, but internal losses increase
Solution Approach 1:
The patent employs parameter changes by optimizing the doping concentration of aluminum or titanium within a specific range (0.001 to 0.03 mol fraction). This parameter optimization enables the material to achieve improved rate performance at high currents while minimizing internal losses through enhanced electronic conductivity and structural stability at the optimal doping level.
3Speed
If electrode resistance is reduced to improve rate performance, then rate capability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the doping process with the standard cathode material synthesis process. By incorporating aluminum or titanium doping into the existing co-precipitation and calcination steps, the patent reduces electrode resistance to improve rate capability while avoiding additional complex manufacturing stages. The doping elements are introduced together with the main cathode materials in a single synthesis sequence.
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 cathode active material enhances lithium-ion battery performance by increasing rate capability and reducing electrode resistance without compromising capacity or safety, making it suitable for high-current applications in vehicles.
Implementation Method 1
adding an aqueous solution of water-soluble salts of nickel, cobalt and manganese and a solution of alkali metal hydroxide to the slurry according to step (a), thereby co-precipitating a layer of a mixed hydroxide of nickel and cobalt and manganese hydroxide on the particles according to step (a)
Implementation Method 2
removing particles of (NiaCobMncAld)(OH)2+d or (NiaCobMncTid)(OH)2+2d so obtained and drying them in the presence of oxygen
Data Source
AI summary
The present invention is directed towards a process for making a particulate material according to the general formula (I): NiaCObMncMd(O)x(OH)y, wherein M is selected from Al and Ti, x is in the range of from 0.01 to 0.9, y is in the range of from 1.1 to 1.99, a is in the range of from 0.3 to 0.85, b is in the range of from 0.05 to 0.4, c is in the range of from 0.1 to 0.5, d is in the range of from 0.001 to 0.03, with a+b+c+d=1 said process comprising the following steps: (a) providing an aqueous slurry of particles of aluminum hydroxide or titanium dioxide, (b) adding an aqueous solution of water-soluble salts of nickel, cobalt and manganese and a solution of alkali metal hydroxide to the slurry according to step (a), thereby co-precipitating a layer of a mixed hydroxide of nickel and cobalt and manganese hydroxide on the particles according to step (a), (c) removing particles of (NiaCObMncAld)(OH)2+d or (NiaCObMncTid)(OH)2+2d so obtained and drying them in the presence of oxygen.