Composite Negative Electrode for Solid-State Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries with lithium metal negative electrodes face issues of volume expansion and lithium dendrite penetration due to random lithium deposition, leading to safety concerns and capacity loss during charging.
Innovation Solution
A composite negative electrode structure comprising a current collecting layer, a porous layer with carbon nanomaterials, and lithiophilic structures, where the lithiophilic structures act as nucleation points for orderly lithium deposition within the pores of the porous layer, reducing the formation of solid electrolyte interface and preventing lithium dendrite penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium metal negative electrode is used to achieve high energy density, then energy density is improved, but random lithium deposition causes volume expansion and lithium dendrite penetration
Solution Approach 1:
The patent introduces a porous layer with lithiophilic structures as an intermediary between the current collecting layer and the solid-state electrolyte layer. This intermediary structure guides lithium ion deposition along predetermined pathways, preventing random deposition and dendrite formation while maintaining high energy density benefits of lithium metal electrodes
Solution Approach 2:
The patent employs a porous layer containing lithiophilic structures that provide controlled pathways for lithium ion deposition. The porous structure allows orderly accommodation of deposited lithium, preventing volume expansion and dendrite penetration while maintaining electrical conductivity and ion transport
2Use of energy by moving object
If lithium metal negative electrode is used to achieve high energy density, then energy density is improved, but volume expansion occurs due to random lithium deposition
Solution Approach 1:
The porous layer with lithiophilic structures provides predetermined spaces and pathways for lithium deposition, accommodating volume changes without causing external expansion. The porous structure absorbs the volumetric changes during lithiation-delithiation cycles, preventing battery swelling
Solution Approach 2:
The patent creates local lithiophilic structures within the porous layer that selectively attract and guide lithium deposition to specific locations. This localized control ensures uniform distribution of lithium, preventing localized swelling and maintaining overall battery volume stability
3Manufacturing precision
If porous layer with high specific surface area is used to promote orderly lithium deposition, then deposition pattern is improved, but solid electrolyte interface forms excessively
Solution Approach 1:
The lithiophilic structures within the porous layer create localized regions with enhanced lithium affinity, concentrating deposition activity at these specific sites rather than across the entire porous layer surface. This selective localization reduces the effective surface area forming SEI, minimizing irreversible capacity loss while maintaining orderly deposition
Solution Approach 2:
The patent modifies the chemical and physical parameters of the porous layer by incorporating lithiophilic structures with specific surface properties. These parameter changes create preferential deposition sites that guide lithium ions, reducing random deposition on high-surface-area regions that would otherwise form excessive SEI
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 composite structure alleviates volume expansion, reduces irreversible capacity, and enhances safety by promoting orderly lithium deposition, thereby improving the performance and reliability of solid-state batteries.
Implementation Method 1
the lithiophilic structures can enable the lithium ions in the solid-state battery to be reduced at the lithiophilic structures to form lithium metal. The lithium metal formed can then expand and grow outward with the lithiophilic structure as a nucleation point
Implementation Method 2
the lithiophilic structures can enable the lithium ions in the solid-state battery to be reduced at the lithiophilic structures to form lithium metal
Implementation Method 3
the porous layer can alleviate the volume expansion of the negative electrode during charging, and the lithiophilic structures can enable the lithium ions in the solid-state battery to be reduced at the lithiophilic structures
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A composite negative electrode structure includes a current collecting layer, a porous layer, a plurality of lithiophilic structures, and a solid-state electrolyte layer. The porous layer is located on a surface of the current collecting layer and includes a plurality of pores. The lithiophilic structures are located on the surface of the current collecting layer and accommodated in some of the pores. The solid-state electrolyte layer is located on the porous layer.