By replacing traditional silicon or graphite anode materials with specially crystallized niobium, manufacturers can overcome some of the safety and power limitations of traditional lithium-ion batteries (LIBs). Echion Technologies Ltd. (Cambridge, U.K.; www.echiontech.com) has developed a proprietary mixed niobium-oxide active material, XNO®, which has been specifically engineered to extend battery cycle life and accelerate charging rates for heavy-duty applications. These performance boosts are mainly due to XNO’s unique crystal morphology, which is based on the Wadsley-Roth shear block structure that promotes fast intercalation of lithium ions.
Source: Echion
“These are inorganic chemical structures that have arrangements of metal and oxygen octahedra in them, predominantly niobium, with six oxygens connected to it, combined with some oxygen sharing in the structure. This oxygen sharing means that instead of a perfect octahedral lattice, you have shear planes throughout that provide rigidity and stability. When you put lithium ions in, there are wide open pores for them to flow through at great speed, which are resistant to detrimental rotation or distortion,” explains Alex Groombridge, co-founder and chief technology officer of Echion Technologies.
The rigidity and stability created by the Wadsley-Roth niobium structure enables what Groombridge calls a “lithium-ion highway” where the ions can efficiently move in and out of the structure “tens of thousands of times while remaining very stable,” which promotes much faster charging than conventional LIB anodes. Also, since the chemical potential at which lithium moves through the niobium-based active material is higher than silicon or graphite, lithium does not metallicize and cause safety risks, an issue that is particularly exacerbated at faster charging rates with existing battery technologies.
Echion produces XNO using an inorganic solid-state manufacturing process. The company is currently producing its active materials at a 2,000-ton/year plant in Brazil, in collaboration with CBMM (Minas Gerais, Brazil; www.cbmm.com), the world’s largest niobium supplier, and is working to develop applications in the heavy-industrial and energy-storage markets. “We will have a live client trial in Western Australia at a lithium mine using a 200-ton truck, which will be hybridized with an Echion niobium-based battery technology to really prove it in the market,” notes Groombridge.