For a lengthy time, tin remained an almost unnoticed commodity. However, the metal is now a market darling – largely through its reinvention as a tech metal.
The highly regarded Massachusetts Institute of Technology (MIT) has labelled tin as the base metal most likely to be impacted by new technology and that type of reputation saw its price on the London Metal Exchange (LME) hit historic highs above US$36,770 per tonne in late September this year. This compares to a price of around US$13,000/t just over 18 months previously.
Notably, the three-month tin price on the LME has traded on average above US$30,000 per tonne since June, rising by around 70% since January of this year. The dramatic rise is linked to a steady demand increase, with tin now linked to “green energy” and, in particular, rechargeable batteries and electric vehicles (EVs).
While tin demand remains steady at the moment, specialists are forecasting that the growing battery market and the metal’s potential in other new technologies will lead to an increase in desire for the ancient metal.
The International Tin Association says energy uses and technologies are the strongest new use drivers, with tin additions to lead-acid batteries and solder used for joining solar cells already benefiting.
It suggests that over the next decade tin has many opportunities in lithium-ion and other batteries, solar PV, thermoelectric materials, hydrogen-related applications and carbon capture.
The Association believes Tin may be the “forgotten EV metal”.
“As other commodities gain public attention, tin is quietly gaining momentum as a performance enhancing component in all of the three generations of advanced anode materials that have been road-mapped to 2030, plus some solid state technologies,” the Association stated.
“Several hundred papers and patents have tracked development of tin-based materials to maximum theoretical capacity and even beyond. Although the field is highly competitive, startups and major OEMs are starting to signal their interest in tin and International Tin is monitoring developments with keen interest.”
Booming prices have fuelled a significant surge in exploration across the globe
LIB boost
New research has shown that tin nanoparticles are key to stabilizing silicon-graphite anodes in lithium-ion batteries (LIBs).
Studies have found that adding just 2% tin can dramatically improve silicon conductivity in anodes, for example.
Research at Argentina’s National University of Cordoba showed “an emergent effect of the interaction between tin and silicon” in graphite anodes. The team ground up tin, silicon, and graphite powders in a 1:1:1 ratio. The resulting nanoparticle mix was heated for two hours to create an anode.
Subsequent cutting-edge experiments showed this composite anode could maintain energy transfer at a high rate in a lithium-ion battery cell, even after 100+ charging cycles. The scientists concluded that tin provided a physical constraint, preventing the silicon and graphite nanoparticles separating and ultimately extending the silicon-graphite anode lifetime.
The Tin Association says silicon has, for some time, been touted as the material to improve the performance of lithium-ion anodes. In theory, silicon anodes have an energy density ten-times that of graphite. During charging, however, lithium-ions insert themselves into silicon anodes, forcing the electrode to expand to four times its original size. Research such as this aims to find ways to prevent the anode fracturing, failing, and cutting short the battery life.
Tin is also very much in the race to improve anode performance, either alone or as a synergist with silicon and other materials.
Another area where tin is leading the way in the energy equation is its use in lead-acid batteries, especially in China. Its demand there is expected to grow steadily with the introduction of more start-stop and micro-hybrid vehicles, as well as growth in alternative energy and telecoms markets.
Other battery technologies
Whilst the current focus is on lithium-ion batteries, the next generation of cheaper, safer products is already in development, including sodium-ion, magnesium-ion, potassium-ion and other products. Tin, and its alloys and compounds, are prominent candidates for anode materials in some of these, and a growing number of developments, including tin, are noted. Although performance of some prototypes already exceeds commercial lithium-ion products, it is likely that such products will find their own market space and indeed some are already being used in niche markets.
It is generally agreed that energy uses and technologies are the strongest new use drivers for tin. Along with its addition to lead-acid batteries, there is an expected link to the metal for solar PV, thermoelectric materials, hydrogen-related applications, and carbon capture.
Critical mineral
A number of other battery technologies are under development, particularly for larger scale utility power storage. For tin, there may be opportunities in the liquid metal technologies or as a catalyst in redox flow batteries, for example. Some very recent work on ion-exchanging technologies includes tin as a possible metal-ion candidate.
Booming prices have fuelled a significant surge in exploration across the globe. One company that is making hay while the sun shines is Venture Minerals Limited (ASX: VMS) which has reported significant recent exploration drilling success in Tasmania.
The company successfully intersected 11m of new sulphide rich skarn typical at Mount Lindsay, one of the largest undeveloped tin projects in the world, containing in excess of 80,000 tonnes of tin metal.
This latest discovery follows the recent success targeting extensions of the Renison Mine Sequence where drilling intersected 16m of potentially tin bearing sulphide rich, magnetite skarn, located along strike from Renison Bell, one of the world’s largest and highest-grade tin mines.
Venture Minerals says the two recent discoveries clearly demonstrate the tin exploration potential of the Mount Lindsay Project, which is located within Australia’s premier tin district.
The Mount Lindsay Project is already classified by the Australian government as a Critical Minerals Project, with an advanced Tin-Tungsten asset which is significantly enhanced by the discovery of two new skarn zones – one within the Renison Mine Sequence in the Mount Lindsay area and the other along strike of Mount Lindsay’s main tin deposits. Australia recognizes the metal as a fundamental metal to the battery revolution and new technology.
