A Chinese research team has developed a new calcium-ion battery that may one day replace the ubiquitous lithium storage unit, with scientists saying it offers lower production costs, a higher power density and a longer lifespan at room temperatures.
Lithium, now used in most electrochemical storage systems and electronic devices, is relatively expensive because of limited supplies and has technical disadvantages. Calcium-ion batteries, long tipped as a viable replacement, have at least twice the number of electrons as lithium units, which means higher power density in a thinner, lighter package.
The search for alternatives is mostly due to demand for extended-range electric vehicles and batteries for portable gadgets that can give a longer life span, as well as a need to reduce manufacturing costs. Calcium, the fifth most common metal in the Earth’s crust, is about 2,500 times more abundant than lithium in its natural state, which will make it a cheaper storage solution.
The Chinese researchers have had to overcome some technical issues, including the need to find the right combination of electrode materials and electrolytes. In response, a team at the Chinese Academy of Science Shenzhen Institutes of Advanced Technology has developed a hybrid device using activated carbon as a positive electrode and tin as a negative electrode, which offers satisfactory cycling performance and output voltage.
Their rechargeable calcium-ion prototype battery can reportedly retain 84% of its initial capacity after 1,000 cycles at room temperature, offering high energy density, cost reductions due to its abundance in nature and low ion mobility, among other benefits.