Since the basic materials make up over half of the initial cost of cell in which the cathode material (cobalt, nickel and manganese) is the largest contributor, so there is a financial incentive to recover cathode material. Further, the value of cathode material is greater than that of cells other constituents, so the recovery of reusable cathode provides more revenue. Recovery of cobalt from LCO cathode by smelting or leaching recovers about 70% of the cathode value, a percentage that falls drastically for other cathode chemistries containing less cobalt. This could be a considerable advantage for direct recycling, also called “Cathode-to-Cathode” recycling, because of the importance of cathode value recovery. The recovery process should ensure that quality of these recovered cathode materials is at par with the quality of virgin materials and must not be contaminated or degraded.
Future of Li-Ion Cells
Unfortunately, Moore’s Law9 of Semiconductors does not apply on cells (LICs included)! If we go back to the introduction of the mass market of LIC in 1991 the cell capacities have only improved about 5%~6% per year. The cell technology has also not advanced so as to double the energy densities every year. In fact it has only improved about eightfold since the first commercial batteries were introduced in 1854 i.e. over about 170 years.
So the question is “how would the Cells/Batteries of future look like?” Is there really a “game changing” or “disruptive” technology out there in this field of energy storage (read cells/ batteries)? Unfortunately, the answered is clear “No”, since by definition & application a disruptive technology is the one which entirely changes the way things are done in present times. In early 1900, evolution of ICEV was a disruptive technology (as it completely changed the travel behaviors of society and the way people used to travel, till them).
The rise of PCs the 1980s was a disruptive technology (as it completely changing the way offices, school & businesses functioned back them). In 1990s, the touch phone technology was a disruptive technology (it changed the social interaction of people & the way they communicate & interact). However, the evolution of present day’s LIC from the first Lead Acid Cell was patented in 1859 by Gaston Planté of France, does not show the same pattern as all the technologies have been coexisting and complimenting to each other. To becoming a true disruption technology, LICs technology need to bring out an innovation with much improved energy storage, higher power densities, both at much lower cost apart from being safer.
On the other side, while, the oil, being liquid, has the advantage of in its handling & transporting, but it also, is a very convenient energy source, it also as a very high sp. energy density @ 46 MJ/kg, whereas present day LICs only offer sp.energy densities between 0.36 MJ/Kg to 0.90 MJ/Kg which is about 1/128th ~ 1/85th of the energy of oil. This in turn means no present day batteries will be able to completely replace the oil as fuel (which also means that EVs can never completely replace ICEVs). In order to displace a ICEVs, the battery technology must get smaller (volumetrically) & safer while at the same time increasing in energy and power densities to a point where it is on par with the oil.
Even if any battery technology starts offering the same energy content as a liquid fuel, but the cost is exorbitantly high it will not become a feasible solution to be acceptable for mass market adoption. From an automotive standpoint, once any technology is engineered into a vehicle it is likely to last somewhere between 5 to 10 years as that is about the life of a standard vehicle architecture. This means that the batteries of EVs which are being introduced today, were actually designed, using batteries technologies that are minimum three to five years old and any breakthrough in battery technology, happening today, would only be available on EVs, few years down the line. This cycle will continue for many years to come. However, the silver lining for EVs is that while oil needs to be pumped out from wells impacting nature, and since the oil is a non-renewable energy source, they become scarce with time, costing higher with passage of time, electricity can be generated from multiple renewable energy sources without impacting the Mother Nature (e.g. solar, wind, geo thermal, tidal, etc.)
Epilogue: While the theoretical energy density improvement, that can be gained using silicon or thinner anodes in LIC, is in the range of 300% or more, the practical energy density increase is often about one-third of this theoretical number. However, if the theoretical number of energy densities are achieved, it will almost bring LICs at par with liquid fuels.
So what could happen to the battery technologies that could make LIC truly disruptive? That is difficult to say, as Lithium is already one of the lightest materials in the periodic table and so there is no visible opportunity of improvement in the lithium-based cell technology, and hence perhaps the disruption may not come by the lithium base cell technologies, but from the any other new material chemistries. We are already beginning to see some of these chemistries emerging in the portable power industry, as we see personal electronics getting smaller and thinner and perhaps even wearable. However, since these appliances tend to have much shorter life as compared to the EVs or stationary energy storage applications, the new improvement in cell technologies need to prove their worth with EVs/ large energy storage applications.
Yet, there is a lot of work is going on with nano-materials, coating the silicon or tin with graphite, graphene or other materials, organic electrolytes, as well as new methods for manufacturing, etc. that may improve the performance of the present day cell chemistries to make them at par with present day liquid fuel oil based energy sources. Perhaps, one of the most interesting new technologies that is in development is the solid state battery (SSB).
Another battery technology that is also receiving a lot of research attention today is the lithium-air battery & offers extremely high energy density, very flat discharge curves, essentially unlimited shelf life as long as it is not exposed to air, has low cost, and no environmental issues. Some other technologies include fuel cells (micro fuel cells, automotive fuel cells, and very large fuel cells) and super capacitors and ultra-capacitors. However, there are many challenges with them also, the biggest of which is that it is dependent on the environment for the oxygen and it has limited power output capacity. However, there are many challenges with them also which needs to be tackled for their long term acceptability as replacement of liquid fuel (i.e. Oil) and emerge a disruptive technology.
