PNNL develops zinc metal dual-ion battery for safe and cost-effective energy storage

According to foreign media reports, scientists have created a working battery using a new dual-ion chemistry. Compared with existing lithium-ion batteries, this battery can avoid the use of many rare or expensive materials and has a lower risk of fire. At the same time, the battery shows good performance and several performances are expected to be further improved.

(Photo source: pv-magazine)

In the quest to overcome the limitations of today’s lithium-ion technology, less attention has been paid to dual-ion batteries, in which both positively and negatively charged ions can effectively store energy. These batteries have great potential for high energy density using low-cost and safe materials, but stability and electrolyte performance issues at higher voltages are difficult to overcome. Despite this, the dual-ion concept remains an area of ​​interest for scientists, and a joint project between American and German teams may further advance the technology.

Led by the Pacific Northwest National Laboratory (PNNL) in the United States and the University of Münster in Germany, the research team created a "zinc metal water-based dual-ion battery." The battery consists of a zinc negative electrode, a natural graphite positive electrode, and a concentrated hydrogen peroxide electrolyte. During testing, the battery showed a voltage of up to 2.5V and a capacity of about 110mAh/g at a charge and discharge current of 200mA/g. When the current reached 5000 mA/g, the capacity dropped to 60mAh/g. After 200 cycles, the battery can still maintain 80% of its initial capacity.

The team said that other discoveries made during the study showed that the performance of this battery could be further optimized. Ismael Rodriguez, a PNNL researcher, said: "During the study, we successfully elucidated the basic mechanism of negative ion embedding in graphite in a water-based system through experimental work and computer simulations, providing important insights for further research on dual-ion technology for grid energy storage."

The research team believes that its experimental prototype can be developed into a battery with sufficient energy density to be used in grid-scale storage applications, even if not for electric vehicles or other smaller devices. "The system obviously needs to be optimized, but the research shows that this high-capacity energy storage system has great potential for development, which is not only safe but also cost-effective."