Porous Separator Inhibits Metal Ion Migration in Lithium Batteries
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Solution Overview
Problem
Current lithium battery manufacturing processes are complex, costly, and prone to safety issues due to metal fragment embedment, and the use of transition metals like manganese and nickel in cathodes leads to reduced battery cycle life from ion migration.
Innovation Solution
The development of battery stacks with a porous separator comprising inorganic oxides or nitrides, an anionic compound, and a current collector, which inhibits the migration of transition metal ions and enhances safety by preventing electrical short circuits, using a reusable substrate for cost-effective and efficient production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If metal substrates are slit into discrete battery stacks during manufacture, then battery production can be achieved, but metal fragments are embedded into the separator causing short circuits and safety issues
Solution Approach 1:
The patent removes the metal substrate layer from the battery structure entirely, extracting the problematic element that causes metal fragment embedment during slitting. The battery is constructed with electrode layers directly on a porous separator without a metal current collector substrate, eliminating the source of metal fragments that cause short circuits and safety issues during the slitting process.
2Ease of manufacture
If transition metals like manganese and nickel are used in cathodes to reduce cost, then battery cost decreases, but metal ions migrate through the separator reducing battery cycle life
Solution Approach 1:
The patent introduces a porous separator with specific pore size (10-100 nm) and surface properties as an intermediary layer between the cathode containing transition metals and the anode. This separator acts as a selective barrier that allows lithium ion transport while blocking the migration of larger transition metal ions (manganese, nickel, cobalt) that would otherwise deposit on the anode and reduce battery cycle life.
Solution Approach 2:
The patent employs a porous separator made of ceramic materials or coated porous polymer with controlled pore sizes of 10-100 nm. The porous structure enables lithium ion conduction while the pore size restriction and surface charge properties prevent the passage of larger transition metal ions, thus maintaining battery cycle life despite using cost-effective transition metal cathodes.
3Ease of manufacture
If conventional interleaving processes are used to construct lithium batteries, then battery assembly can be achieved, but manufacturing becomes slow, complex and expensive
Solution Approach 1:
The patent merges multiple discrete battery layers (electrode layers, separator, current collectors) into a single integrated structure where electrode layers are coated directly on the porous separator. This consolidation eliminates the need for complex interleving processes, manual assembly steps, and multiple handling operations, enabling continuous high-speed manufacturing and significantly improving productivity.
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 solution enables the production of lithium batteries with improved safety and extended cycle life by controlling metal ion migration and reducing production costs through automated, high-speed processing.
Implementation Method 1
a porous separator interposed between the cathode and anode, wherein the separator comprises an anionic compound... which inhibits the migration of transition metal ions
Data Source
AI summary
Provided is a lithium battery, wherein the battery comprises an anode, a cathode, wherein the cathode comprises one or more transition metals, an electrolyte, and a porous separator interposed between the cathode and anode, wherein the separator comprises an anionic compound. Also provided are methods of manufacturing such batteries.