Aligned Carbon Nanofiber/Nanotube Electrodes for Energy Storage Devices

Technology

Problem: Li-ion batteries have low gravimetric capacities (typically 1000-4000 mAh/gcarbon)-Tortuous pore structure limit the accessibility of electrolyte to available carbon surface area and can choke off electrolyte transport pathways during discharge-Require the addition of polymeric insulating binder material to improve mechanical integrity of electrodes and ensure good electrical connection between particles. Technology: This invention proposes the synthesis of MWCNT electrodes for Lithium-Air batteries. Lithium-Air batteries consist of a Li metal cathode an organic electrolyte and a high-surface carbon anode. During discharge Li ions migrate to the anode and combine with electrons and molecular oxygen to form solid LixO2. MWCNT electrodes can also be used in non-aqueous electrochemical capacitors.

Benefits

1) Theoretical gravimetric energy density is 3-5 times higher than Li-ion. 2) Well developed and highly interconnected pore structure. 3) Binder-free electrodes for lithium-air electrodes lower the weight of electrodes while maximizing the accessible carbon surface area exposed to electrolyte. 4) Process is adaptable to porous substrates with larger available surface areas (such as a metal mesh or carbon paper). 5) Convenient for manufacturing and cell assembly.

Date of release