They power tiny phones and two-tonne electric cars. They form the guts of a growing number of grid-storage systems¹ that smooth the flow of electricity from wind and solar power stations. Without them, the electrification needed to avoid the worst effects of global warming would be unimaginable.

But lithium-ion (Li-ion) batteries have downsides. Lithium is scarce, for one. And the best Li-ion batteries, those with layered-oxide cathodes, also require cobalt and nickel. These metals are scarce, too — and cobalt is also problematic because a lot of it is mined in the Democratic Republic of Congo, where working conditions leave much to be desired. A second sort of Li-ion battery, a so-called polyanionic design that uses lithium iron phosphate (LFP), does not need nickel or cobalt. However, such batteries cannot store as much energy per kilogram as layered-oxide ones.

A group of companies, though, think they have an alternative: making batteries with sodium instead. Unlike lithium, sodium is abundant: it makes up most of the salt in the oceans. And chemists have found that layered-oxide cathodes which use sodium rather than lithium can get by without cobalt or nickel to increase their quality. The idea of making sodium-ion (Na-ion) batteries at scale is therefore gaining traction. Engineers are adjusting designs. Factories, particularly in China, are springing up. For the first time since the Li-ion revolution began, lithium’s place on the electrochemical pedestal is being challenged.

(www.economist.com, 25.10.2023. Adaptado.)

1 grid-storage system: sistema de armazenamento de energia elétrica.

They power tiny phones and two-tonne electric cars. They form the guts of a growing number of grid-storage systems¹ that smooth the flow of electricity from wind and solar power stations. Without them, the electrification needed to avoid the worst effects of global warming would be unimaginable.

But lithium-ion (Li-ion) batteries have downsides. Lithium is scarce, for one. And the best Li-ion batteries, those with layered-oxide cathodes, also require cobalt and nickel. These metals are scarce, too — and cobalt is also problematic because a lot of it is mined in the Democratic Republic of Congo, where working conditions leave much to be desired. A second sort of Li-ion battery, a so-called polyanionic design that uses lithium iron phosphate (LFP), does not need nickel or cobalt. However, such batteries cannot store as much energy per kilogram as layered-oxide ones.

A group of companies, though, think they have an alternative: making batteries with sodium instead. Unlike lithium, sodium is abundant: it makes up most of the salt in the oceans. And chemists have found that layered-oxide cathodes which use sodium rather than lithium can get by without cobalt or nickel to increase their quality. The idea of making sodium-ion (Na-ion) batteries at scale is therefore gaining traction. Engineers are adjusting designs. Factories, particularly in China, are springing up. For the first time since the Li-ion revolution began, lithium’s place on the electrochemical pedestal is being challenged.

(www.economist.com, 25.10.2023. Adaptado.)

1 grid-storage system: sistema de armazenamento de energia elétrica.

Read the text 1 to answers the questions 26 and 27

Text 1

Education for Sustainable Development

With a world population of 7 billion people and limited natural resources, we, as individuals and societies, need to learn to live together sustainably. We need to take action responsibly based on the understanding that what we do today can have implications on the lives of people and the planet in future. Education for Sustainable Development empowers people to change the way they think and work towards a sustainable future.

UNESCO aims to improve access to quality education on sustainable development at all levels and in all social contexts, to transform society by reorienting education and help people develop knowledge, skills, values and behaviours needed for sustainable development. It is about including sustainable development issues, such as climate change and biodiversity into teaching and learning. Individuals are encouraged to be responsible actors who resolve challenges, respect cultural diversity and contribute to creating a more sustainable world.

(https://en.unesco.org. Adaptado.)