The US Argonne National Laboratory is claiming significant progress in developing sodium-ion batteries and says the chemistry needs development and refining.
Venkat Srinivasan, LENS (Low-cost Earth-abundant Na-ion Storage) consortium director, told BEST Argonne is leading a multilab group consisting of six universities. The big cathode laboratory has studied a new design of cathodes for sodium-ion batteries. By applying new heat treatment methods, the formation of cracks in the cathode synthesis can be eliminated, preserving the energy storage performance for a long period.
Srinivasan said: “We also develop a better electrolyte using artificial polyanions in cooperation with the Berkeley university. They are projects with a high risk of failure, but if we succeed, we will break the ceiling. We are looking at anodes made of hard carbon, usage of tin, various alloys, phosphate etc. The goal is to minimise degradation of the material, which is a weakness with lithium-ion batteries.”
He added the density of the material is still too low. “It is kind of ‘fluffy’. We need to synthesise for higher density, which means higher capacity of the cells to maximise the energy contents. There are no magic answers in battery design – but with our team of 80 people, researchers, students, post-doctoral researchers, we achieve new results together with the industry, which participates in our advisory board and builds robust interaction with manufacturers.
“Argonne is a research institution, and we create an ecosystem through collaboration. We are also agnostics, and we want to spread the knowledge about sodium-ion batteries and their place in the world of batteries, shepherding the transition towards a sustainable world.”
He notes the US does not control the supply chain of conventional lithium-ion batteries and so different technologies are needed, including domestic sources of raw materials.
“Lithium-phosphate batteries are a cheaper option, but if we are able to find solutions to remove cobalt and eventually nickel from the batteries and replace them with easily available sodium, it will be a great leap towards a more resilient future.
“First of all, there are some facts about sodium-ion batteries. The energy density is lower than for lithium-ion. Our R&D projects must therefore find out how far we can push sodium – where are the limits? Safety and costs are important factors. We must cut the cost levels – the consumer must be able to buy more affordable battery products. The materials should be recyclable, and we must clarify what to do at the end of the life cycle.”
Photo: Venkat Srinivasan, senior scientist at Argonne and director of the Low-cost Earth-abundant Na-ion Storage (LENS) consortium. Argonne
