01 November 2012

Silicon Anodes For Three Times More Efficient Lithium Ion Batteries Being Developed

Lithium Ion batteries are ubiquitous in the world today. Most, if not all, electronic devices run on lithium ion batteries. Even electric powered cars run on these kind of batteries.


These batteries can be used individually or arranged as part of a group of cells to power electric or hybrid vehicles.

Parts of a Battery

A lithium ion battery as well as other types of batteries are composed of three major components:
  • The Anode (-)
  • The cathode (+)
  • The electrolyte
The anode and the cathode are hooked up to an electrical circuit attached to the device being powered.

A battery gives of electrical energy when ions from the anode travel to the cathode. When the ions move from the cathode to the anode, the battery is recharged. In both ways, the ions pass through the electrolyte.

The faster the ions can move to the anode through the electrolyte dictates how quickly the battery can be recharged. Graphite is used as the material for the anode but only allows one lithium atom to pass per six carbon atoms. Prior to graphene, silicon was the material of choice since it allows four lithium atoms to pass per one silicon atom, giving it a faster recharge cycle.

Silicon is considered the superior material for anodes since it can hold 10 times more lithium ions than graphite. But there's a problem: Silicon more than triples its volume when completely lithiated. When repeated, this contraction and expansion causes silicon to quickly break down and cause fragmentation in the battery

Refining Silicon Based Lithium Ion Batteries


Video: Lithium-ion batteries: How do they work?





Because of the fragmentation that occurs in the battery when silicon is used, graphite has always been the standard material despite it being inferior to silicon.

Crushing Silicon


Image: Madhuri Thakur/Rice University




A Battery Three Times Better


A half-cell battery that incorporates a porous silicon developed at Rice University has achieved more than 600 charge-discharge cycles in the lab. The work holds promise for next-generation batteries for electric vehicles.
Image: Jeff Fitlow/Rice University



Rice University
Scientific Reports
Lockheed Martin Advanced Nanotechnology Center of Excellence at Rice (LANCER)
Renewable Battery Cathode Produced from Pulp and Paper Waste
MIT News: The Future of Battery Technology: Liquid Metal Energy
Using Graphene And Nanotechnology To Build A Faster Edison Battery
The Eco Friendly Hybrid Car
Piezoelectricity: Using Viruses and Nanotechnology To Generate Electricity