Tin is called the ‘spice element’ because a little of it is present everywhere in ways that are essential to our quality of life. Tin use in vehicles is a good example. Listed below are the current main uses of tin. More in depth information, including market research, can be found on the website of the International Tin Association.
Thanks to the positive growth forecasts for electronics and solar cell markets, as well as continued conversion to lead-free soldering, the long-term outlook for solder usage remains balanced or slightly positive.
Tin chemicals for PVC stabilisers, polymer catalysts and numerous other applications is the second largest tin use, with steady growth. They look likely to retain this position for the foreseeable future, with new uses in energy materials in prospect longer term.
Tinplate is mainly used in food cans as well as in some beverage cans, general line cans for chemicals, paints and dry products and also in can ends. Global consumption of tinplate remains static or declining with new opportunities in emerging economies and circular economy regulation.
Tin use in lead-acid batteries, especially in China, is expected to grow steadily with the introduction of more start-stop and microhybrid vehicles as well as growth in alternative energy and telecoms markets.
Copper Alloys & Other Uses
Copper alloys including bronze are still widely used in applications ranging from sculpture to electrical products. Tin and other alloys, including powders and coatings, are used in brake pads, roofing, engineering, bearings and numerous other ways. Traditional pewter giftware is still highly valued and tin wine capsules are used in luxury wines and spirits.
TIN AND NEW TECHNOLOGY
There were more than 5,000 scientific papers and patents on tin related technologies published in 2017 demonstrating a strong future for this versatile element.
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. Over the next decade tin has many opportunities in lithium ion and other batteries, solar PV, thermoelectric materials, hydrogen-related applications and carbon capture. R&D, startups and corporate investments related to these innovations will be highlighted.
Lithium Ion Batteries
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 roadmapped to 2030, plus some solid state technologies. 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.
Post Lithium Ion Batteries
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, 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.
Other Battery Technologies
A number of other battery technologies are under development, particularly for larger scale utility power storage. For tin there may be opportunities in 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.
Tin was early in the race for new ‘earth abundant’ materials to replace expensive and rare elements used in current solar PV technologies such as gallium. The first generation product was a ‘kesterite’ copper tin zinc sulphide (CZTS) developed by IBM. More recently tin has gained attention in ‘lead-free’ perovskite products that have dramatically competitive performance, targeted at new markets for example on architectural glass. Tin is also being explored as a heat energy storage medium on solar farms that concentrate sunlight using mirrors. Apart from the materials themselves, this sector is already benefitting tin use in China particularly through increased use of solder ribbon used to join solar cells, and increased associated electronics production.
Tin is often part of complex multi-component materials developed to convert heat energy, especially waste heat, into useful electricity, known as thermoelectric materials. Indeed tin selenide has been hailed as ‘the worlds best’ thermoelectric material due to its unique crystal structure. A large number of materials are under development for different temperature ranges and environments including simple products such as zinc tin oxides or tin sulphides as well as more sophisticated products such as ‘Huesler’ alloys such as nickel manganese tin.
The hydrogen economy is still largely in the future as a concept, but there are already some uses and an increasing investment in visionary projects such as the hydrogen aeroplane. Tin has already been shown to have potential to significantly reduce the costs and sustainability of hydrogen production technologies, notably in use as a liquid metal to strip carbon from methane and as an oxide or sulphide photocatalyst to split water in sunlight.
Fuel cells are used to combine hydrogen and oxygen over a catalyst to produce electricity and tin has been shown to make an important contribution to some key components in the technology. Liquid tin was first used as an electrode in a type of fuel cell that was able to convert any type of hydrocarbon gas feed and at the same time act as catalyst the recombinant reaction. Other developments have used tin, its alloys and compounds in various physical parts of the fuel cell, including tin pyrophosphate as a medium temperature fuel cell membrane.
Carbon Capture Catalysts
The race is on to find and develop catalysts that can convert climate change gases, notably carbon dioxide, to useful industrial chemicals such as formate. Although there are numerous candidates, tin has a special ability to reform and join organic compounds that can be exploited, using sunlight or electrochemistry. An increasing number of studies are using tin as the active component, or as a promotor in other catalyst systems.