Silicon Anode 3D Nanoporous Graphene Core
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional carbonaceous anodes in Li-ion batteries face limitations due to substantial volume change, intrinsic low conductivity, and unstable solid electrolyte interphase (SEI) films, which hinder the practical implementation of silicon anodes despite their promising specific capacity and working potential.
Innovation Solution
A 3D bi-continuous nanoporous graphene core with a silicon layer sandwiched between the graphene core and an ion-conductive hybrid silicate layer, preventing electrolyte infiltration and stabilizing the SEI, enhancing conductivity and structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If silicon is used as anode material to achieve high specific capacity, then energy density is improved, but volume change during cycling increases causing structural instability
Solution Approach 1:
The patent employs a flexible graphene shell enclosing the silicon core, allowing the structure to accommodate volume changes during lithium insertion/extraction. The graphene thin film acts as a buffer that maintains structural integrity while permitting the necessary expansion and contraction of the silicon anode material during cycling.
Solution Approach 2:
The patent creates a composite structure combining silicon with graphene and conductive polymer materials. This composite approach leverages the high capacity of silicon while the graphene and polymer components provide structural stability, conductivity, and flexibility to withstand volume changes during electrochemical cycling.
2Use of energy by moving object
If silicon anode is implemented to achieve high capacity, then energy storage is improved, but intrinsic low conductivity reduces rate capability
Solution Approach 1:
The patent forms a composite structure where silicon is combined with highly conductive graphene and conductive polymer materials. This composite design maintains the high energy storage capacity of silicon while the conductive components create efficient electron transport pathways, significantly improving rate capability and power density.
Solution Approach 2:
The patent applies different materials with specific properties to different regions of the anode structure. The silicon core provides high capacity, while the graphene shell and polymer matrix provide conductivity and flexibility. This local differentiation of material properties optimizes both energy storage and power delivery throughout the electrode structure.
3Use of energy by moving object
If silicon anode is used to achieve high specific capacity, then energy density is improved, but unstable SEI films increase impedance
Solution Approach 1:
The patent introduces graphene and conductive polymer materials as intermediary layers between the silicon anode and the electrolyte. These intermediary materials form stable SEI films that protect the underlying silicon from direct contact with the electrolyte, preventing continuous SEI formation and impedance growth while still allowing lithium ion transport.
Solution Approach 2:
The graphene shell and polymer film act as flexible protective barriers that stabilize the SEI interface. These thin films accommodate volume changes of the silicon core while maintaining a stable, low-impedance interface with the electrolyte, ensuring reliable long-term cycling performance.
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 hybrid anode achieves high reversible capacity, long cycling lifespan, and excellent rate capability, with stable SEI formation and improved mechanical flexibility, addressing the challenges of volume change and conductivity issues in silicon anodes.
Implementation Method 1
an electrically conductive porous graphene core
Implementation Method 2
an ion-conductive hybrid silicate layer disposed on the silicon layer
Data Source
AI summary
An electrode includes an electrically conductive porous graphene core; a silicon layer disposed on an internal surface of the porous graphene core; and an ion-conductive hybrid silicate layer disposed on the silicon layer.