A uniquely successful collaboration between Altris AB and the Uppsala cell development company LiFeSiZE AB has resulted in a sodium-ion battery cell that is not only competitive with lithium-ion batteries, but greatly improves upon it in every key sustainability criteria. The cell matches the performance, life-cycle and energy density of a lithium-ion battery based on a LFP cathode—but contains far more sustainable materials, has a more sustainable production method and is much easier to recycle. The cell was financially supported by the Swedish Energy Agency and is unquestionably the most sustainable high performing battery cell ever produced.
As the drive to reduce dependency on fossil fuels escalates, so does the demand for batteries and the materials to produce them. Electric cars, power tools, heavy duty vehicles, grid and home batteries – the need is rising, all whilst raw materials for lithium-ion batteries become more scarce or ethically troubling to extract.
‘Altris set out with the vision to create a highly reliable, sustainable and high-performance sodium-ion battery to rival its lithium-ion counterparts’ says Adam Dahlquist, Altris CEO. ‘This is technology that has the potential to revolutionise the industry, improve the sustainability of batteries and lower manufacturing costs’
The battery is based on Altris’ groundbreaking Fennac®—a cathode material that is made up of elements that are widely abundant and have no geo-political sourcing issues: iron, air, seawater and wood. The performance of the material has many similarities with lithium iron phosphate (LFP) in that it has approximately the same voltage and capacity, with no thermal runway. Compared to LFP though, Fennac® removes the need to use copper in the battery cell, saving both on weight and cost.
Beyond the Fennac® based cathode, each and every one of the cell’s components are drastically improved compared to rival lithium-ion cells with regards to the sustainability of the materials used. The cell is made up of:
- A hard carbon anode made from biomass (from the paper industry or coconut shells), as opposed to mined graphite. Industry standard graphite requires harsh chemical treatments to be used and when the battery is no longer useful, so there is a high likelihood that its stored carbon will be released into the atmosphere. Synthetic graphite alternatives that exist also require tremendous amounts of energy to produce.
- A fluorine free and non-flammable electrolyte that is made up of elements available in abundance. Using a fluoride free electrolyte avoids the big problems experienced with the industry standard polyfluorinated carbon chains (PFOS) and LiPF6.
- A bio-based binder for the anode and cathode (as opposed to the fluorine based binders that are standard in lithium-ion batteries).
- A water solvent for the cathode and anode coating (eliminating the need for a very energy consuming handling of the industry standard and poisonous NMP compound).
- A cellulose-fibre based separator, from renewable forestry products (as opposed to the fossil fuel oil-based products commonly used in lithium-ion batteries).
- The cell in essence also becomes a carbon sink and when recycled. It will not add any CO2 into the atmosphere as any other type of battery would.
The composition and safety of this type of cell makes it ideally suited for applications where large battery installations are required at a low cost, with the highest possible safety standards. Typical uses would include urban or large-scale energy storage, shipping/marine applications and industrial equipment. Altris and LiFeSiZE have together developed 300 mAh cells (which have been cycled more than 100 times) and an 800 mAh cell (which is still undergoing cycle testing).
In the coming months, Altris and LiFeSiZE will continue to work together to optimise the cell’s cycling parameters, the last stepping stone before producing larger cells. Bigger battery cells will then be produced (up to 10 Ah), with greater energy density (more than 100 Wh/kg) as well as testing the life cycle performance to a commercial level (more than 500 cycles). The cells will also undergo advanced fire testing.
Altris believes that all batteries should enable a renewable future without an increase in cost to the customer or the environment. To this end, Altris is currently collaborating with Swedish, European and Asian partners to introduce this technology to the mass market.