More Energy, Less Cost
Despite the breakthrough, building the ideal battery requires more than perfecting the anode. A cathode that matches the high capacity anode is required to unleash the boost in energy density, but current cathodes do not have enough capacity to match the lithium metal anode.
Zeta’s second key innovation is a hybrid cathode created from sulfur and carbon, which has 8 times the capacity of current cathodes based on metal oxide. Thus, Zeta’s anode-cathode combination means a packaged lithium-sulfur battery with three times the energy storage capacity of lithium-ion batteries.
Further, Zeta has eliminated the use of expensive metals such as cobalt in its battery. That translates to a significant reduction in battery cost. Though others have been trying to develop sulfur-based cathode for decades, they just could not get it to cycle well, and the battery dies after just a couple of hundred cycles at most. Maslin explained that Zeta has succeeded in stabilizing the sulfur cathode and pointed to test results that show it can be cycled with minimal capacity loss over thousands of cycles.
Furthermore, the Zeta lithium-sulfur battery does not self-discharge to any appreciable extent and holds charge for a significantly long time, thus boasting a superb shelf life. A major battery performance concern is self-discharge – you charge the battery then store it, but when you use it later, only a fraction of the stored battery capacity is left.
Based on Zeta’s measurements, it is estimated that more than 90% of its battery capacity will remain after 10 years of storage at full charge, unlike regular lithium-ion batteries that will have at best 10% capacity over the same period of storage. That means the Zeta battery is ready to work after virtually any period of storage.
In summary, the Zeta battery addresses both energy density and safety. Test results published in several scientific journals including Nature Magazine show that the Zeta battery has:
- Up to 3 times the energy storage capacity of lithium-ion batteries
- Faster charge time (minutes instead of hours)
- Lower battery temperature
- Little degradation over charge/recharge cycles
- Outstanding shelf life
- Significantly lighter than lithium-ion batteries
- Zero cobalt
- Significantly lower cost than lithium-ion batteries
If their research and test results are accurate, Zeta Energy may hold the new gold standard in energy storage. The technology appears to address multiple shortcomings of current lithium-ion batteries and has done so at a lower price point. These are exactly the kinds of breakthroughs that are needed if battery storage is to be adopted widely by utilities seeking to smooth out the intermittency of renewables like wind and solar power.