Offset Solid-State Battery Stacks for Dendrite Control
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Solution Overview
Problem
Lithium-sulfur batteries face challenges in cycle life, sulfur utilization, mass fraction of sulfur in the positive electrode, and rate capability, limiting their commercial viability.
Innovation Solution
A solid-state battery design with a bipolar configuration and microstructured composite separators that inhibit dendrite formation, allowing for flexible electrodes and improved ion transport, along with offset base layers and multiplexors for independent monitoring and control of cell stacks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium metal negative electrode is used to achieve high specific energy, then energy density is improved, but cycle life deteriorates due to volume changes and dendrite formation
Solution Approach 1:
The patent changes the physical state of the electrolyte from liquid to solid, which fundamentally alters the interaction between lithium metal and the electrolyte. The solid electrolyte maintains mechanical contact with the lithium metal anode while preventing dendrite formation and accommodating volume changes during cycling, thus preserving both high specific energy and cycle life
Solution Approach 2:
The patent employs composite solid electrolyte materials that combine multiple functional properties: ionic conductivity for lithium ion transport, mechanical strength to prevent dendrite penetration, and flexibility to accommodate volume changes. This composite approach allows the system to maintain high energy density while improving cycle life
2Quantity of substance
If high-capacity positive electrode active material is used to maximize capacity increase, then specific capacity is improved, but voltage is reduced due to reaction at lower voltage
Solution Approach 1:
The patent utilizes solid electrolyte interface (SEI) formation control and surface modification techniques to enable high-voltage operation with high-capacity materials. The solid electrolyte prevents side reactions and maintains stable interfacial conditions, allowing the system to achieve both high specific capacity and high voltage simultaneously
3Device complexity
If conventional battery design is used for simplicity, then device complexity is reduced, but manufacturing precision deteriorates due to alignment requirements of offset base layers
Solution Approach 1:
The patent employs asymmetric offset base layer design where the base layers extend beyond the electrode edges by specific amounts. This asymmetric geometry provides built-in alignment features that guide the stacking process and ensure proper positioning of subsequent layers, thereby improving manufacturing precision without significantly increasing device complexity
Solution Approach 2:
The offset base layers are designed to protrude before electrode assembly, creating pre-positioned alignment features. This preliminary geometric configuration ensures that subsequent layers automatically align correctly during stacking, reducing the need for complex alignment mechanisms and improving manufacturing precision
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
Enhances cycle life, sulfur utilization, and rate capability, enabling a higher specific energy and energy density, thus making lithium-sulfur batteries more commercially viable.
Implementation Method 1
a first solid-electrolyte separator positioned between a first cathode and a first anode
Implementation Method 2
microstructured composite separators that inhibit dendrite formation
Data Source
AI summary
In one embodiment, a solid state battery includes a first cell stack including a first solid-electrolyte separator positioned between a first cathode and a first anode, a first base layer including a first base portion positioned directly beneath the first anode, and including a first lateral extension extending laterally beyond the first anode, a second cell stack beneath the first base layer and including a second solid-electrolyte separator positioned between a second cathode and a second anode, a second base layer including a second base portion positioned directly beneath the second anode, and including a second lateral extension extending laterally beyond the second anode, wherein the second base portion extends laterally beyond the first lateral extension, and a multiplexor (i) in electrical communication with the first base portion through the first lateral extension, and (ii) in electrical communication with the second base portion through the second lateral extension.