The survey paper, “Titanium Niobium Oxide: From Discovery to Application in Fast-Charging Lithium-Ion Batteries”, is behind an American Chemical Society paywall that wants US$ 40 for 48 hour reading privilege. It isn’t on Sci-Hub, but I did find a copy on ResearchGate with embedded full text.
ResearchGate: “Titanium Niobium Oxide: From Discovery to Application in Fast-Charging Lithium-Ion Batteries”
Here is the abstract.
Lithium-ion batteries are essential for portable technology and are now poised to disrupt a century of combustion-based transportation. The electrification revolution could eliminate our reliance on fossil fuels and enable a clean energy future; advanced batteries would facilitate this transition. However, owing to the demanding performance, cost, and safety requirements, it is challenging to translate new materials from laboratory prototypes to industrial-scale products. This Perspective describes that journey for a new lithium-ion battery anode material, TiNb2O7 (TNO). TNO is intended as an alternative to graphite or Li4Ti5O12 with better rate and safety characteristics than the former and higher energy density than the latter. The high capacity of TNO stems from the multielectron redox of Nb5+ to Nb3+, its operating voltage window well above the Li+/Li reduction potential prevents lithium dendrite formation, and its open crystal structure leads to high-power performance. Nevertheless, the creation of a practical TNO anode was nonlinear and nontrivial. Its history is built on 30 years of fundamental science that preceded its application as a battery anode, and its battery development included a nearly 30-year gap. The insights and lessons contained in this Perspective, many of them acquired firsthand, serve two purposes: (i) to unite the disparate studies of TiNb2O7 into a coherent modern understanding relevant to its application as a battery material and (ii) to highlight briefly some of the challenges faced when scaling up a new material that affect TiNb2O7 as well as new electrode candidates more generally.
I had wondered about the abundance of Niobium, recalling that SpaceX has recently started using a shorter nozzle in the Merlin Vacuum engine used on the second stage of the Falcon 9 (see comment #5 on “SpaceX Transporter-7 Launch” posted here on 2023-04-11) in order to reduce the cost of the niobium from which it is primarily made. I tried to find price information and charts for niobium, but it was like looking for financial data on the Internet in 1994—everything was either ten years out of date of a pitch for an overpriced industry report from some outfit you’ve never heard of. Here is what the Griffith et al. paper has to say about availability (section 4.4, “Bringing a New Element to the Market”).
It is reasonable then to wonder whether a new element, particularly a 4d transition metal, can be adopted and whether the supply chain exists at the scale relevant to the modern lithium-ion battery market. The annual production of niobium in 2019 was about 74,000 tons, primarily as ferroniobium alloy used for high-strength steel applications, whereas the {\rm Li}_4{\rm Ti}_5{\rm O}_{12} market currently stands at an estimated 3000 tons. In 2018, Toshiba Corporation partnered with CBMM, a niobium producer, to develop and manufacture {\rm Ti}{\rm Nb}_2{\rm O}_{7} at the pilot-scale manufacturing facility in Kashiwazaki, Japan. Together, the companies are working to provide battery cells and modules based on the TNO anode technology. Considering that niobium is a critical element, like other battery components including lithium, cobalt, manganese, graphite, titanium, and to a lesser extent, nickel, supply partnerships are important. This may be particularly true for resources such as niobium that have few suppliers.