MWCNT Cathode Composition for High-Rate Lithium-Ion Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion batteries face challenges in achieving high rate capability and cycle life due to low conductivity of conductive carbon used in electrodes, along with safety concerns related to thermal runaway.
Innovation Solution
A cathode electrode composition comprising carbon fused metal and hetero atom doped multi-walled carbon nanotubes (MWCNT) prepared from refinery feedstock, combined with active material, carbon black, and a polymer binder, which enhances conductivity and adhesion properties, thereby improving the rate capability and cycle life of lithium ion batteries while ensuring safety through effective heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional conductive carbon is used in lithium ion battery electrodes, then manufacturing cost is reduced, but conductivity and rate capability deteriorate
Solution Approach 1:
The patent uses composite materials by combining carbon nanotubes with metal particles (such as cobalt, nickel, or copper) to create carbon fused metal composites. This composite structure provides both the high conductivity needed for rate capability and the mechanical strength for adhesion, resolving the contradiction between performance and cost by using a synergistic material system rather than pure expensive carbon nanotubes
Solution Approach 2:
The patent changes the physical and chemical parameters of the conductive carbon by controlling the carbonization process temperature (700-900°C) and the ratio of carbon nanotubes to metal particles. By optimizing these parameters, the material achieves enhanced conductivity and adhesion properties that improve rate capability while maintaining cost-effectiveness through controlled material composition
2Reliability
If high surface area carbon material is used to improve rate capability, then conductivity increases, but adhesion property and cycle life deteriorate
Solution Approach 1:
The carbon fused metal composite combines the high surface area carbon nanotubes (providing rate capability) with metal particles (providing adhesion and structural stability). The metal component acts as a bridge that enhances both electrical conductivity and mechanical adhesion to the active material, resolving the contradiction between rate capability and cycle life stability
Solution Approach 2:
The carbon fused metal composite performs multiple functions simultaneously: it provides electrical conductivity for electron transport, mechanical adhesion for electrode stability, and thermal conductivity for heat dissipation. This multi-functionality allows a single material to address multiple performance requirements without compromise
3Ease of manufacture
If conventional carbon materials are used in electrodes, then manufacturing simplicity is maintained, but thermal runaway safety deteriorates
Solution Approach 1:
The patent changes the thermal properties of the electrode material by incorporating metal particles with high thermal conductivity into the carbon matrix. This parameter change in thermal conductivity enables efficient heat dissipation throughout the electrode, preventing localized hot spots that could lead to thermal runaway, while the overall manufacturing process remains relatively simple
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 use of carbon fused metal and hetero atom doped MWCNTs in lithium ion battery cathodes results in high rate capability, extended cycle life, and improved safety by maintaining stable performance and preventing thermal runaway, with the added benefit of using indigenously produced materials at a lower cost.
Implementation Method 1
Carbon nanotubes have extremely high tensile strength, high modulus, good chemical and environmental stability and high thermal and electrical conductivity
Implementation Method 2
MWCNT is prepared from petroleum refinery feed stock. MWCNT is metal and heteroatom doped CNT wherein metal is transition metal like Co, Mn, Fe, Ni etc. and heteroatom is nitrogen, sulphur, oxygen, phosphorus etc.
Implementation Method 3
MWCNT is metal and heteroatom doped CNT wherein metal is transition metal like Co, Mn, Fe, Ni etc. and heteroatom is nitrogen, sulphur, oxygen, phosphorus etc.
Data Source
AI summary
The present invention relates to a high rate capable lithium ion battery/cell with carbon fused metal and hetero atom doped multi walled carbon nanotubes (MWCNT) as conductive carbon for electrode is fabricated. Cathode electrode is prepared with active material along with high interfacial area carbon fused metal and heteroatom doped MWCNT prepared from petroleum refinery feed stock wherein metal is transition metal like Co, Mn, Fe etc. and heteroatom is nitrogen, sulphur, oxygen, phosphorus etc. Active material is selected from may comprise NMC, LFP, NCA, LNMO, LCO, LMO or combination thereof. Lithium ion full cells of 2032 coin cells were fabricated using the above materials as cathode with graphite anode is high rate capable of deliver capacity up to 5 C rate, deliver specific capacity of 80-100 mAhg−1 at 1 C rate and exhibit good cycling stability at same rate when cycled between 2.75-4.2V.