Three-dimensional conductive fiber current collector for batteries
Solution Overview
Problem
Existing battery technologies face challenges in improving cathode and anode conductivity, leading to limitations in power and energy density due to mechanical integrity issues and the need for thicker electrodes, which are not effectively addressed by current materials like carbon black, carbon nanotubes, and graphene.
Innovation Solution
Incorporation of conductive nonwoven structures made from metal or metal-coated fibers into the cathode or anode, which can be fabricated to enhance conductivity and mechanical integrity, allowing for thicker electrodes without significant thickness or weight increase, using methods such as electroplating or chemical vapor deposition to coat the nonwoven structure after fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carbon black, carbon nanotubes, or graphene are used to improve cathode conductivity, then electrical conductivity is enhanced, but cost, manufacturability, and dispersion issues arise
Solution Approach 1:
The invention changes the physical form of conductive additives from fine powders (carbon black, nanotubes, graphene) to continuous metal-coated fibers. This parameter change from particulate to fibrous morphology fundamentally alters dispersion behavior and manufacturability while maintaining conductivity enhancement.
Solution Approach 2:
The invention uses composite metal-coated fibers (e.g., nickel-coated carbon fibers, copper-coated polyester fibers) that combine the conductivity of metals with the structural benefits of fibrous reinforcement. This composite approach solves both conductivity and manufacturability issues simultaneously.
2Quantity of substance
If thicker electrodes are used to increase energy density, then more capacity is stored, but mechanical integrity deteriorates and conductivity decreases
Solution Approach 1:
The invention transitions from two-dimensional planar electrodes to three-dimensional porous structures built on nonwoven fiber substrates. This dimensional change allows increased capacity while maintaining mechanical integrity through the fibrous network architecture.
Solution Approach 2:
The invention employs porous nonwoven fiber substrates with controlled void spaces that provide both mechanical strength and pathways for electrolyte penetration. The porosity allows thick electrodes to maintain integrity while accommodating active material without compromising conductivity.
3Reliability
If metal-coated fibers are used to improve conductivity, then resistance is reduced, but fiber length precision and coating uniformity must be controlled
Solution Approach 1:
The invention specifies controlled fiber length ranges (0.5-5mm) and coating thickness parameters to optimize conductivity while maintaining manufacturability. These parameter specifications balance electrical performance with manufacturing precision requirements.
Solution Approach 2:
The invention applies metal coating locally on fiber surfaces rather than requiring perfect uniformity throughout. The coating is applied to provide sufficient conductivity at fiber contact points and surfaces, accepting natural variations in coating thickness while achieving reliable electrical performance.
4Reliability
If nonwoven structures are used as current collectors, then conductivity and mechanical support are improved, but fabrication complexity increases
Solution Approach 1:
The nonwoven fiber structure serves multiple functions simultaneously: it provides mechanical support, acts as a current collector, and serves as a substrate for active material deposition. This multi-functionality reduces overall device complexity despite the sophisticated structure.
Solution Approach 2:
The metal-coated nonwoven fabric performs multiple roles: structural reinforcement, electrical conductivity pathway, and catalyst support. This universal application of a single component simplifies the overall battery architecture by eliminating separate elements for each function.
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 conductive nonwovens enhances both power and energy density by providing consistent conductivity and mechanical support, enabling thicker electrodes with improved electron transport and reduced resistance, resulting in faster charging and discharging with lower Joule heating and increased efficiency.
Implementation Method 1
the addition of a few percent of high aspect ratio metal coated fibers (such as nickel, copper, or aluminum on a fiber such as carbon) may be mixed into the active cathode material or the active anode material to improve the conductivity
Implementation Method 2
using methods such as electroplating or chemical vapor deposition to coat the nonwoven structure after fabrication
Implementation Method 3
using methods such as electroplating or chemical vapor deposition to coat the nonwoven structure after fabrication
Implementation Method 4
The purpose of a battery is to store electrons and then deliver them when needed. Simply described, the electrons are stored in the anode and then released from the cathode
Implementation Method 5
resulting in faster charging and discharging with lower Joule heating and increased efficiency
Data Source
AI summary
A battery electrode for a battery being either a cathode and/or an anode is provided with enhanced electrical conductivity for use in a battery. The cathode having an active cathode material and/or the anode having an active anode material. The active cathode material is infused into a conductive nonwoven structure and/or the active anode material is infused into a conductive nonwoven structure. The conductive nonwoven structures are selected from metal nonwoven structures (comprised of metal fibers) and metal-coated nonwoven structures (comprised of metal-coated fibers). The metals and metal coatings may be selected from metals including nickel, aluminum, copper, silver, and other metals. The metal-coated nonwoven structure may be a metal-CVD coated nonwoven structure. The conductive nonwoven structure may be secured to a foil current collector using adhesive, by thermal sintering, or other methods of adherence.