Silicon-Embedded Copper Nanostructure Networks for Battery Anodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium-ion batteries face challenges in achieving high energy density and long cycle life due to the lithiation-induced swelling of silicon anodes, which leads to cracking and disconnection of active material layers.
Innovation Solution
The development of silicon-embedded copper nanostructure networks, where copper nanostructures are integrated with silicon nanostructures to form a conductive network that maintains electrical pathways even during lithiation-induced swelling, preventing disconnection and enhancing energy density and cycle life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon is used as anode material to increase lithium storage capacity, then energy density is improved, but the anode structure stability deteriorates due to 400% expansion upon lithiation causing cracking
Solution Approach 1:
The silicon anode is divided into nanowire segments rather than using bulk silicon. This segmentation into smaller nanoscale units allows the silicon to accommodate lithiation expansion without developing the critical stresses that lead to cracking in bulk materials, thereby maintaining structural stability while achieving high lithium storage capacity
Solution Approach 2:
Copper nanostructures are embedded within and around the silicon nanowires, creating a nested composite structure. The copper nanowires and nanoparticles are positioned inside and along the silicon nanowires, forming a hierarchical nested architecture that provides both mechanical support and electrical conductivity throughout the anode structure
Solution Approach 3:
The invention creates a composite anode material combining silicon nanowires with copper nanostructures (nanowires and nanoparticles). This composite structure leverages the high lithium storage capacity of silicon while the copper component provides mechanical reinforcement and maintains structural integrity during lithiation cycles, preventing the cracking that occurs in pure silicon anodes
2Quantity of substance
If silicon expands 400% upon lithiation to achieve high capacity, then energy density is improved, but electrical conductivity is lost due to cracking and disconnection
Solution Approach 1:
The copper nanostructures are locally distributed throughout the silicon anode structure, with copper nanowires embedded within silicon nanowires and copper nanoparticles positioned at strategic locations. This local distribution ensures that electrical conductivity is maintained at every point within the anode, even as silicon expands during lithiation, preventing disconnection and maintaining reliable electron transport pathways
Data Source
AI summary
Provided herein are nanostructure networks having high energy storage, electrochemically active electrode materials including nanostructure networks having high energy storage, as well as electrodes and batteries including the nanostructure networks having high energy storage. According to various implementations, the nanostructure networks have high energy density as well as long cycle life. In some implementations, the nanostructure networks include a conductive network embedded with electrochemically active material. In some implementations, silicon is used as the electrochemically active material. The conductive network may be a metal network such as a copper nanostructure network. Methods of manufacturing the nanostructure networks and electrodes are provided. In some implementations, metal nanostructures can be synthesized in a solution that contains silicon powder to make a composite network structure that contains both. The metal nanostructure growth can nucleate in solution and on silicon nanostructure surfaces.