Stabilized Lithium Metal Powder Anode Coating for Irreversible Capacity Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium-ion battery technology faces challenges in achieving high-energy density and power output due to high irreversible capacity loss and low coulombic efficiency, particularly with nanoscale active material particles, which require inefficient SEI formation and energy-consuming electrically charged formation processes.
Innovation Solution
The use of stabilized lithium metal powder (SLMP) with a thin lithium salt coating, prelithiation to compensate for lithium loss, and a solution-processed slot-die coating method with polymer binders to achieve uniform and scalable SLMP coatings on anode surfaces, reducing SEI formation inefficiencies and enhancing battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If nanoscale active material particles are used to reduce diffusion length and enhance reaction kinetics, then power output is improved, but first cycle irreversible capacity loss increases due to larger SEI formation area
Solution Approach 1:
The patent applies preliminary action by adding stabilized lithium metal powder (SLMP) to the anode before battery operation. This SLMP serves as a pre-loaded lithium reservoir that compensates for the lithium consumed during SEI formation in the first cycle. The SLMP is incorporated into the anode structure along with nanoscale active material particles, creating a dual-component system where the SLMP sacrificially provides lithium ions to form the SEI layer, thereby preserving the nanoscale particles' capacity for reversible lithium insertion and extraction.
2Reliability
If excess cathode material or lithium salt concentration is increased to compensate for capacity loss, then coulombic efficiency is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts the lithium compensation function from the cathode material and lithium salt reservoir and relocates it to the anode side through SLMP. Instead of adding excess cathode material or increasing lithium salt concentration in the electrolyte, the invention places stabilized lithium metal powder directly in the anode structure. This extraction simplifies the overall battery design by eliminating the need for excess cathode capacity or high lithium salt concentrations, thereby reducing device complexity and manufacturing cost while maintaining high coulombic efficiency.
3Manufacturing precision
If SLMP is added to binder solution to form slurry and deposited as film, then uniform coating is achieved, but manufacturing process complexity increases
Solution Approach 1:
The patent employs hydraulic principles by using a liquid binder solution (containing polymers and solvents) to form a slurry with SLMP and nanoscale active material particles. This slurry is then deposited as a uniform film on the anode substrate through solution processing techniques. The liquid medium enables homogeneous distribution of all components and facilitates uniform coating formation, achieving manufacturing precision through the hydraulic carrier medium while maintaining relative process simplicity.
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 approach significantly improves first cycle coulombic efficiency and long-term cycling performance, reducing the need for excess cathode material and energy-intensive formation processes, while maintaining high-energy density and power density in lithium-ion batteries.
Implementation Method 1
dissolving styrene-butadiene-rubber (SBR) and polystyrene (PS) in xylene to form a binder solution
Implementation Method 2
adding stabilized lithium metal powder (SLMP) to the binder solution to form a slurry
Implementation Method 3
exposing the film and substrate to a drying process to form the electrode structure
Data Source
AI summary
A simple solution processing method is developed to achieve uniform and scalable stabilized lithium metal powder coating on Li-ion negative electrode. A solvent and binder system for stabilized lithium metal powder coating is developed, including the selection of solvent, polymer binder and enhancement of polymer concentration. The enhanced binder solution is 1% concentration of polymer binder in xylene, and the polymer binder is chosen as the mixture of poly(styrene-co-butadiene) rubber (SBR) and polystyrene (PS). Long-sustained, uniformly dispersed stabilized lithium metal powder suspension can be achieved with the enhanced binder solution. A uniform stabilized lithium metal powder coating can be achieved with simple doctor blade coating method and the resulting stabilized lithium metal powder coating can firmly glued on the anode surface. With the prelithiation of negative electrode by stabilized lithium metal powder, improvements in electrochemical performances are demonstrated in both graphite/NMC and SiO/NMC full-cell.