Ceramic-Coated Li-Ion Electrodes Without Separators
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Solution Overview
Problem
Lithium-ion batteries with conventional separator membranes face issues such as increased internal resistance, limited cycle life, and safety hazards due to short circuits and thermal runaway, especially in batteries without tabs.
Innovation Solution
A lithium-ion battery design that replaces the separator membrane with a ceramic coating on the electrodes, using specific particle size distributions and binders to enhance safety and cycle life, and maintains thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separator membrane is used to isolate electrodes, then safety is improved by preventing short circuits, but internal resistance increases and cycle life is limited
Solution Approach 1:
The patent changes the material parameter from organic polymer to inorganic ceramic coating, which fundamentally alters the thermal and electrical properties. The ceramic coating maintains safety functionality while preventing the degradation issues of organic separators, thereby extending cycle life without compromising safety
Solution Approach 2:
The patent uses composite ceramic coatings combining multiple ceramic materials (such as alumina, boehmite, silica) with specific particle size distributions. This composite approach optimizes both the protective safety function and the long-term stability, resolving the contradiction between safety and cycle life
2Reliability
If organic polymer separator membrane is used, then electrode isolation is achieved, but thermal stability deteriorates due to melting and carbonization
Solution Approach 1:
The patent changes the material from organic polymer to inorganic ceramic, fundamentally altering the thermal properties. Ceramic materials maintain structural integrity at high temperatures where organic materials would melt or carbonize, thus improving thermal stability while maintaining electrode isolation functionality
Solution Approach 2:
The patent eliminates the need for traditional disposable organic separator membranes by using durable ceramic coatings that provide long-term thermal stability and protective functionality without the limitations of organic materials
3Reliability
If separator membrane thickness is increased to improve safety, then protection is enhanced, but volumetric specific energy decreases
Solution Approach 1:
The patent changes the material properties to achieve superior protection with thinner layers. Ceramic coatings provide enhanced protective functionality at reduced thickness compared to organic separators, thereby maintaining safety while increasing volumetric specific energy
Solution Approach 2:
The patent replaces the mechanical separator membrane system with a ceramic coating system that achieves protective functionality through different mechanisms, enabling thinner design with equivalent or superior protection and higher energy density
4Ease of manufacture
If batteries are designed without tabs to reduce internal impedance, then processing is simplified and internal impedance is reduced, but short-circuit current increases causing thermal runaway
Solution Approach 1:
The patent uses composite ceramic coatings with optimized particle size distributions to provide enhanced protective functionality. This allows tabless battery design to maintain simplified processing while the ceramic coating prevents harmful short-circuit currents and thermal runaway
Solution Approach 2:
The patent applies ceramic coatings beforehand to electrode surfaces to create a protective barrier against short circuits. This prior cushioning prevents thermal runaway before it can occur, enabling safe tabless battery design with simplified processing
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 ceramic coating improves safety by preventing short circuits, increases cycle life, and enhances thermal stability while maintaining high volumetric specific energy.
Implementation Method 1
the ceramic coating formed on an electrode with a specific particle size distribution can replace the battery separator membrane
Implementation Method 2
the ceramic coating improves safety by preventing short circuits, increases cycle life, and enhances thermal stability
Data Source
AI summary
The present invention provides an electrode ceramic coating comprising a ceramic powder and a binder, wherein the particle size of the ceramic powder has a D50 of 0.05 μm-0.6 μm, preferably 0.07 μm-0.4 μm, more preferably 0.09 μm. The present invention further provides a lithium-ion battery comprising a cathode electrode, an anode electrode, electrolyte and a housing, wherein the cathode electrode includes a cathode collector and a cathode active material coated thereon, the anode electrode includes an anode collector and an anode active material coated thereon, and wherein the cathode electrode and the anode electrode face each other, and at least one of surfaces of the cathode electrode and the anode electrode that face each other has a ceramic coating. The ceramic coating can replace the battery separator membrane in the conventional sense, and can improve the cycle life and the thermal stability of the lithium-ion battery.