Silicon Anodes Having A Nano-Vault Structure

A novel silicon anode that provides increased energy capacity and cyclability simultaneously for lithium-ion battery.

A novel silicon anode that provides increased energy capacity and cyclability simultaneously for lithium-ion battery.

Abstract

Silicon (Si) based materials are a promising alternative to graphite anodes for high-energy lithium-ion batteries (LIBs) because of their tenfold increase in theoretical capacity. However, the huge Si volume change during lithiation and delithiation causes electrode fracture and hinders the formation of stable solid electrolyte interfaces (SEIs), reducing the Coulombic efficiency. Here we present a promising Si anode developed by a group of researchers led by Dr. Panagiotis Grammatikopoulos. The silicon anode is formed having a nano-vault like structure. As a result of this structure, the Li-ion battery overcomes the above problems and has improved energy density and long cyclic stability simultaneously.The technology is based on a novel vaulted structure with a resultant arch action that is introduced at the nanoscale. This arch structure demonstrates possibilities for new designs in Si anodes for LIBs and is also eligible for other materials and applications where surface mechanics play a critical role (e.g. hydrogen storage, bio-implants, etc.). The fabrication of the vaulted structure is a result of a three-step growth method leading to columnar amorphous Si films. Arch action is observed exactly when columns contact each other, sealing the anode in a vault-like structure which favors dissipation of stress, preventing Si electrodes from cracking during lithiation/delithiation cycling. Most importantly, the vaulted structure can be piled up repeatedly, thus increasing the amount the Si and both electrode and SEI stability simultaneously.

Applications

  • Batteries
  • Bio-Implants
  • Hydrogen Storage

Advantages

  • Durability
  • Increased Cyclability
  • High Energy Capacity
  • High Coulombic Efficiency

Website

https://groups.oist.jp/tdic/technology0189