The Holy Grail Of Lithium Batteries

Better batteries are needed to economically smooth out the intermittency of renewables like wind and solar power. One company may have finally solved some of the most vexing problems facing lithium-based batteries.

The lithium-ion battery was a solution to this problem. The dendrite problem can be resolved by replacing the lithium-metal electrode with a carbon electrode that has a layered sheet structure (i.e., graphite), which hosts discrete tiny lithium ions between the layers. However, the result is a lower lithium storage capacity than a battery utilizing a solid, continuous lithium-metal electrode.

Solving the Dendrite Problem

An ideal battery would contain solid lithium electrodes while avoiding the dendrite problem. A company called Zeta Energy, using technology licensed from a top university, believes it has created just such a solution.

I recently spoke to Zeta Energy CEO Charles Maslin, who explained that Zeta is the sixth Greek letter and corresponds to carbon, the sixth element in the periodic table. Zeta potential is also a measure of the effective electric charge on a nanoparticle surface.

In an interview I conducted with Maslin, he provided a description of the new battery along with peer-reviewed data from the 10+ years of research and testing that led to its development.

The key innovation in the Zeta battery is a hybrid anode created from graphene and carbon nanotubes. The resulting three-dimensional carbon anode approaches the theoretical maximum for storage of lithium metal – about 10 times the lithium storage capacity of graphite used in lithium-ion batteries.

According to published research, the hybrid anode is one of the best-known conductors of electricity, and when the battery is charged, lithium metal is deposited on the sidewalls of the carbon nanotubes and in the pores between the nanotubes. These are chemically bonded to the surface of the graphene that is in turn chemically bonded to a copper substrate. The graphene-carbon nanotube-copper connections introduce no additional electrical resistance that is typically generated at the interface when electrode materials are coated on copper in batteries. This means no heat is generated at this interface.

The combination of a dendrite-free electrode with the seamless interface enables fast charging and discharging of the Zeta battery, unlike in a graphite-based lithium-ion battery where very fast charging can cause lithium dendrites to form on top of graphite. No resistance at the interface means electrons can travel to the electrode much more rapidly. The Zeta battery can thus be charged safely within a few minutes.