Novel Separator for Electricity Storage Devices

NU 2013-170

Inventors

Harold H. Kung*

Jingmei Shen

Mayfair C. Kung

Cary M. Hayner

Short Description

Reversible, Self-regulating, Temperature-Sensitive Current-limiting Separator for Electrical Energy Storage Devices

Abstract

Northwestern University researchers have developed a novel device to reduce thermal runaway, or loss of energy through heat, in lithium ion batteries. During operation, as batteries discharge stored electricity, some of it is lost as heat. Battery overheating can cause various devices to malfunction as well as lead to fire. Several methods for reducing thermal runaway exist, but they either add complexity to the battery manufacturing process or cause damage to the battery once deployed. Professor Kung and colleagues have invented a reversible thermal control separator (RTCS), which solves both of these problems. RTCS is a graphene oxide based membrane coated with poly(sulfobetaine)polymer, or PMABS. This membrane can easily be integrated into a lithium battery, without the need for any additional components or changes in the manufacturing process. In laboratory tests, RTCS was able to restrict ion flow at elevated temperatures, indicating a reduction in thermal runaway.

Applications

• Lithium ion batteries

Advantages

• Reversible Tunable
• No effect on normal operation
• No additional electronics required

Publications

Shen J, Han K, Martin EJ, Wu YY, Kung MC, Hayner CM, Shull KR, Kung HH (2014) Upper-critical solution temperature (UCST) polymer functionalized graphene oxide as thermally responsive ion permeable membrane for energy storage devices. Journal of Materials Chemistry A, (2).

IP Status

US patent application has been filed