Solid-State Battery Roll-Bonding for Prelithiated Anode Stability
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Solution Overview
Problem
The development of all solid-state lithium secondary batteries faces challenges in achieving sufficient lithium ion diffusivity and maintaining mechanical stability due to volume changes during charging and discharging, leading to degradation and loss of contact between battery components.
Innovation Solution
A method involving continuous roll-bonding of composite sheets to form a prelithiated anode, which includes an aluminum-containing sheet and a lithium-containing layer interposed between a conductive layer and a composite sheet, applying isostatic pressure to inhibit crack formation and enhance lithium ion diffusivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solid electrolyte material is used in all solid-state batteries, then safety and stability are improved, but lithium ion diffusivity is insufficient
Solution Approach 1:
The patent uses composite electrolyte layers combining solid electrolyte material with other materials to achieve both safety/stability and sufficient lithium ion diffusivity. The composite structure allows the solid electrolyte to provide safety benefits while the combined material system maintains ion transport capability.
2Quantity of substance
If electrode volume changes during charging and discharging, then battery capacity is improved, but mechanical stress and loss of contact occur
Solution Approach 1:
The patent introduces buffer layers between the electrode and solid electrolyte, creating segmented structures that can independently accommodate volume changes. These buffer layers act as mechanical decoupling elements, allowing the electrode to expand/contract while maintaining electrical contact and preventing stress concentration.
Solution Approach 2:
The patent modifies mechanical parameters at the interface by introducing layers with intermediate mechanical properties. These buffer layers have tailored elasticity and adhesion characteristics that bridge the mismatch between rigid solid electrolyte and expanding electrode, maintaining stable contact during capacity cycling.
3Stability of the object's composition
If buffer layers are introduced to accommodate volume changes, then mechanical stability is improved, but device complexity increases
Solution Approach 1:
The buffer layers perform multiple functions simultaneously: they accommodate volume changes, maintain mechanical contact, enable lithium ion transport, and provide structural support. This multi-functionality reduces the need for separate dedicated components, thereby limiting the increase in overall device complexity.
Solution Approach 2:
The buffer layers are applied locally only at the electrode-electrolyte interfaces where mechanical stress and contact loss occur, rather than throughout the entire battery structure. This localized approach provides mechanical stability where needed while minimizing the addition of complex components in other areas.
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 method reduces thickness and applies pressure to the composite sheets, forming a prelithiated anode that inhibits crack formation and enhances lithium ion diffusivity, resulting in a cell assembly with improved mechanical stability and specific capacity.
Implementation Method 1
continuously roll-bonding the second composite sheet and the third composite sheet such that the lithium-containing layer and the aluminum-containing layer are compressed together to form a prelithiated anode
Implementation Method 2
achieving and maintaining sufficient lithium ion diffusivity within the solid electrolyte material
Data Source
AI summary
Methods for making solid state battery apparatus are provided. The method comprises continuously supplying a first composite sheet comprising a cathode layer and a solid electrolyte layer formed on the cathode layer. The method comprises continuously supplying an aluminum-containing sheet over the first composite sheet such that the aluminum-containing sheet is placed on the solid electrolyte layer of the first composite sheet. The method comprises continuously roll-bonding the aluminum-containing sheet and the first composite sheet to provide a second composite sheet comprising the cathode layer. The method comprises continuously supplying, over the second composite sheet, a third composite sheet comprising a lithium-containing layer and a conductive layer. The method comprises continuously roll-bonding the second composite sheet and the third composite sheet such that the lithium-containing layer and the aluminum-containing layer are compressed together to form a prelithiated anode.