Vanderbilt researchers have developed a new “anode-free” battery architecture for sodium-ion batteries that provide energy densities in excess of 400Wh/kg, which is greater than the maximum theoretical energy density of a conventional lithium-ion battery.
Sodium ion batteries provide a low-cost framework for energy storage, but current routes to sodium battery design require this advantage to come at the expense of energy density. The technology developed at Vanderbilt greatly improves the energy density for a sodium battery to levels above conventional lithium-ion batteries, involves low-cost materials and aqueous processing, and is compatible with high areal loadings to minimize packaging cost.
- Energy density of greater than 400 Wh/kg
- “Anode-free” battery design with long-term durability (over 1,000 cycles)
- Low-cost aluminum collector materials and aqueous processing methodology
Technology Development Status
Half cell testing of the nucleation layer has shown stable cycling over 1,000 cycles. Full cell testing in coin cell devices with a sodium-containing cathode has demonstrated full-cell energy density of more than 400Wh/kg. Development of the technology is ongoing, including further optimization of the cathode to maximize power density and manufacturing of pouch cell batteries for additional testing.
Intellectual Property Status
A provisional patent application has been filed.
Figure 1: Illustration of the charged and discharged states of the “anode-free” sodium battery utilizing the carbon/aluminum electrode.