Holy graphene: Giving batteries a boost with graphene and tiny holes

A startup spun out of Northwestern University, called SiNode Systems, is building a lithium ion battery using a piece of graphene drilled with tiny holes. The unusual structure can boost the amount of energy that a battery’s anode can hold by ten times, and can also enable the battery to be charged much more swiftly than conventional lithium ion batteries.

While the Evanston, Ill.-based startup is only a year old, it’s made some substantial progress this year, and this month SiNode Systems won over $900,000 in the Rice Business Plan Competition. The startup is now working on raising an additional $1.5 million to bring its technology out of the lab, Guy Peterson, director of commercialization and manufacturing at SiNode, told us in an interview.

SiNode Systems is building on research developed by Northwestern Professor Harold Kung, whose work focuses on the use of a composite of silicon nanoparticles and graphene for the anode part of a battery. A battery is made up of an anode and a cathode and an electrolyte in between, and electrically charged lithium ions flow between the anode and the cathode to discharge or charge the battery.

Figure 2

SiNode’s core intellectual technology involves creating a porous structure in the graphene to speed up the movement of electrons between the anode and the cathode and to stabilize the silicon, creating a sort of scaffolding around it. Silicon swells and contracts quickly and could fall apart easily without a supporting structure.

Lithium ion batteries on the market today typically use graphite for the anode. For the cathode, cobalt oxide is commonly used for consumer electronics while other compounds, such as iron phosphate and manganese oxide are also found in electric cars and power tools.

Lab work has shown that SiNode’s technology could lead to an anode with roughly ten times more energy capacity than the conventional graphite anode, said Guy Peterson, director of commercialization and manufacturing at SiNode. A higher capacity will create a battery that can keep your mobile phone working longer before you have to charge it.

So what does a better anode mean for the overall energy capacity of the battery, which is ultimately what battery retailers and consumers would want to know? Peterson declined to say, partly because the company is still working on that number.

Figure 5

The graphene structure also makes it possible to cut the charging time of the anode by about 10 times compared with the typical charging time of a smart phone at home, Peterson said.

A promising technology needs to marry a low-cost manufacturing process to find success in the market, especially when the technology is targeting the consumer electronics market and there is no shortage of major battery makers and startups working on using silicon and other compounds to improve the anode’s performance (see our list of 13 battery startups to watch).

Peterson said SiNode is working on a production process that promises to be less complicated than some of the existing methods. The process creates a sheet of material at the end rather than a powder.

“A lot of competitors take two steps forward in performance and four steps back in scalability,” Peterson said. “We can offer performance and scalability.”

Figure 3

SiNode plans to supply the anode material or license its technology or both. The company is still working on its business model and manufacturing plans.

From the Rice competition, the startup is set to receive $700,000 in equity investments, $110,000 in cash and $101,400 in office space, marketing and other business services. Before the competition, the company had raised just over $200,000.

Photos courtesy of Northwestern University

Updated at 3:30 PM on April 29, to correct that the technology boosts the amount of energy that a battery’s anode can hold, it does not boost the amount of energy that a battery in general can hold.