1. For years, we have discussed battery recycling as a challenge that would arise once large numbers of electric vehicles began reaching the end of their useful lives. Are we already entering a new industrial phase of recycling?

Yes, and I think one of the keys is understanding that battery recycling does not begin only when large numbers of vehicles reach the end of their useful lives.

There is already a very significant stream of production scrap generated during cell manufacturing. A production line takes time to achieve high yields and, particularly during ramp-up, substantial quantities of off-specification material can be generated. This waste stream also has a particularly interesting characteristic: we know its composition relatively well, and it has generally not undergone the degradation mechanisms associated with battery use. Recovering it and reintroducing it into the production process therefore offers considerable value to cell manufacturers.

At the same time, the volume of end-of-life batteries will gradually increase over the coming years. This means we are moving from a phase in which recycling could be seen primarily as a waste management activity to one in which it can become a strategic part of the battery materials supply chain.

The challenge will be to handle very different feedstocks: relatively homogeneous scrap from gigafactories on the one hand, and end-of-life batteries with different chemistries, manufacturers, states of degradation and designs on the other.

2. What are the main challenges in battery recycling today: recovering more material, reducing process costs or ensuring that recovered materials can be used directly to manufacture new batteries?

Probably all three, but we are placing increasing emphasis on the third.

Historically, much of the effort has focused on maximising the recovery of valuable metals such as nickel, cobalt, copper and lithium. That will remain necessary, but recovering a chemical element does not automatically mean that the resulting material can be used to manufacture a battery again.

There is a crucial distinction between recovering raw materials and recovering battery-grade material suitable for direct reintegration into the production process.

The real goal of a circular battery economy should be to ensure that an ever-greater proportion of recovered materials can be reintroduced into the manufacturing chain with performance comparable to that of virgin raw materials.

At CIC energiGUNE, we are working precisely on this transition. We are interested not only in the extraction stage, but also in purification, impurity control and the reintegration of recovered materials into new electrode formulations. Our approach even envisages integrating hydrometallurgical recovery with the subsequent synthesis of cathode active material, thereby eliminating intermediate steps and improving both the sustainability and overall economic viability of the process.

This matters because the success of recycling should not be measured solely in tonnes recovered, but in how much value we manage to retain within the battery value chain.

3. The expansion of chemistries such as LFP is changing the composition of the battery waste stream. How does this affect recycling economics when high-value materials such as nickel and cobalt are no longer present?

It is one of the most important changes the sector is undergoing.

The traditional economics of lithium-ion battery recycling have been closely linked to the value of certain metals found in NMC or NCA chemistries. When we move to LFP, nickel and cobalt are absent, and the intrinsic value of the material we receive therefore falls significantly.

This forces us to rethink the entire process.

We cannot assume that a recycling model designed around nickel- and cobalt-rich batteries will work equally well when the market composition changes. In fact, the data included in our analysis show very substantial differences in the economic potential of recycling an NMC811 battery compared with an LFP battery.

In this context, factors such as process efficiency, energy consumption, the number of operations required and the ability to recover components that may previously have received less attention become much more important. This distinction, already evident with LFP batteries, will become even more pronounced with sodium-ion batteries. The approach will therefore need to continue evolving and adapting to the particular characteristics of each technology to ensure that it remains applicable to the batteries of the future.

It also reinforces the need for recycling to be flexible enough to accommodate different chemistries. We cannot design a single plant solely around today´s predominant composition, because the technology mix may change significantly over the twenty or thirty years of an industrial facility´s life.

4. Much of the industry has so far focused on pyrometallurgy and hydrometallurgy. What can so-called direct recycling offer, and how ready is it for industrial scale-up?

The concept is very appealing because it seeks to preserve more of the value already added during material manufacturing.

In a conventional process, a battery is dismantled to obtain black mass. Its components are then dissolved, purified and recovered individually, usually as salts. The cathode active material must subsequently be synthesised again from those precursors.

Direct recycling aims to shorten part of this route by preserving or directly regenerating certain materials.

The potential advantage is clear: if we can preserve a high-value structure rather than completely destroying and then rebuilding it, we can reduce processing steps, energy consumption and reagent use.

But the industrial challenge is considerable. Working with a perfectly characterised material in a laboratory is one thing; receiving a real recycling feedstock containing mixtures of NMC111, 532, 622 and 811, LFP, different anodes, aluminium, copper, silicon, phosphorus or degraded materials is quite another. This heterogeneity is precisely one of the main challenges we are studying. Added to this is the need to develop processes capable of recovering materials that can be regenerated while keeping their crystal structure intact, preventing impurities from being carried over and maintaining acceptable recovery yields.

That is why I do not think we should see direct recycling as an immediate replacement for hydrometallurgy, but rather as a family of new routes that may be particularly attractive when sufficiently well-characterised feedstocks are available, such as certain types of manufacturing scrap.

5. Are we moving from an industry whose goal was to recover metals to one whose goal is to recover materials of sufficient quality to be put straight back into a battery?

Yes, clearly. And that is probably one of the most important conceptual shifts in the sector.

If we recycle a battery only to obtain a low-value intermediate product, we are recovering matter but losing much of the technological value created earlier.

The goal must be to move progressively towards a genuine closed loop. That means recovering lithium, nickel, manganese, cobalt, graphite and other components to the specifications required to produce competitive battery materials again.

In our case, we are working on processes that connect recovery, purification and active material synthesis. For example, for NMC materials, hydrometallurgical recovery can be followed by a co-precipitation stage integrated with cathode active material synthesis, rather than treating each operation as a completely separate step. The aim is to move from a depleted battery to new active materials for electrodes, tailored to the needs of the market at any given time.

Increasingly, the question we need to ask will not simply be, ´What percentage do we recover?´, but ´What product are we turning it into, and what value does that product have in a new battery?´

6. Graphite makes up a very significant part of a battery, yet historically it has received much less attention than cathode materials. Could its recovery become one of the next major opportunities in recycling?

I think so. For a long time, the economic focus was mainly on the cathode because that was where high-value materials such as nickel and cobalt were found.

But a battery contains a substantial amount of anode material, and if we really want to maximise circularity, we cannot ignore it.

The challenge is also evolving. We are no longer talking only about graphite. We are beginning to see anodes containing different proportions of silicon, carbon and other materials, which also changes the characteristics of the black mass and the downstream processes. At CIC energiGUNE, we are studying precisely this variability in anode chemistry and the impact of impurities on recycling.

The challenge will be to recover the graphite, remove contaminants and then demonstrate that it retains sufficiently good electrochemical properties for reuse. All of this must be done in close synergy with the recovery of the battery´s other components, ensuring that the different processes do not adversely affect one another.

This is where we have an important advantage as a research centre: we can complete the experimental loop. We do not stop at chemically analysing the recovered material; we can manufacture electrodes and cells from it again and test whether they actually work.

7. To what extent is the real bottleneck upstream of the chemical process, in operations such as discharge, dismantling, sorting and separation of the different battery components? What role can automation and robotics play?

It is fundamental. Sometimes we talk about recycling as though it begins when black mass is ready to enter a chemical reactor, but everything that happens beforehand has a huge influence on what we can do afterwards.

Sorting efficiency is especially important. If we mix LFP batteries with NMC, or even different NMC compositions, we directly change the chemistry of the process feedstock. The same applies to variability in copper, aluminium, graphite, silicon, phosphorus and other impurities, whose presence can affect overall recycling efficiency. The scale of this impact will depend to a large extent on the design and sizing of each industrial plant, as well as the degree of integration between the different process stages.

That is why the future of recycling will also depend on better identification, separation and characterisation systems.

Automation and robotics can play an increasingly important role, particularly as volumes grow. But the biggest leap will probably come from combining automation with information: knowing which battery we are receiving, what its chemistry is and which process is best suited to it.

The better we perform this initial sorting, the easier it will be to design efficient chemical processes and obtain high-purity end products.

8. Europe is introducing increasingly demanding targets for recovery, recycled content and traceability. Can regulation become a driving force behind a genuine European battery recycling industry?

Yes, but regulation alone will not be enough. It can create demand for recycled materials and set minimum recovery targets, which is important for developing a market and providing visibility for investment.

But building a competitive European industry also requires economically viable processes. A recycling plant will not be sustainable in the long term simply because there is a regulatory obligation. It will have to manage highly variable feedstocks, operate at high capacity utilisation and produce outputs whose value justifies capital expenditure, energy, reagents and operating costs.

This brings us to another aspect we consider strategic: process flexibility. A plant built today may face a very different distribution of battery chemistries ten years from now. That is why we are studying routes that can adapt to different NMC ratios, LFP contamination and changes in anode composition.

For Europe, recycling can also provide value beyond waste management: it can become a domestic secondary source of materials and partially reduce dependence on imported raw materials.

9. As new chemistries emerge—sodium-ion, solid-state, lithium-metal and lithium-sulphur—will the recycling industry also have to reinvent itself, or can we develop processes flexible enough to handle different technologies?

I think we will see a combination of both. Some operations will be common to different technologies: dismantling, separation, characterisation and certain mechanical treatments. But we cannot assume that all the chemical processes developed for today´s lithium-ion batteries will transfer directly to every new technology.

Indeed, we can already see the problem within lithium-ion technology itself. Black mass may contain different NMC compositions, LFP contamination, graphite, silicon, copper, aluminium or phosphorus. That variability changes the conditions required for leaching, purification and recovery. If we add sodium-ion, solid-state batteries or new families of anodes and electrolytes, the diversity will be even greater.

That is why I think one of the most valuable industrial capabilities will be to develop flexible recycling platforms that can adapt their operations to the feedstock they receive. This also means that recycling must be incorporated at an earlier stage in the development of new batteries. We should not design a new chemistry first and then ask ourselves twenty years later how to recycle it. Assessing recyclability from the earliest stages of development will become increasingly important, so that circularity becomes another parameter in battery design.

10. What is CIC energiGUNE currently working on in recycling, and which advances do you believe could have the greatest industrial impact over the next five to ten years?

Our approach aims to cover different stages of the value chain. The first line of work concerns the recycling of manufacturing scrap. We are developing mechanical and separation processes that can selectively recover aluminium, copper, cathode active material and anode materials. We are also investigating solvent-based processes to separate active material from the current collector and facilitate its recovery. A second area focuses on black mass. We analyse how different chemistries, proportions of nickel, manganese and cobalt, LFP contamination, anode materials (graphite, Si-C and others) and impurities affect the process. The aim is to develop hydrometallurgical processes flexible enough to work with real feedstocks, rather than only ideal laboratory samples.

A third line of work, probably particularly important for us, is moving beyond the recovery of individual elements towards their reintegration into battery materials. We are working on purification, co-precipitation and cathode active material (CAM) synthesis to reduce processing steps and close the loop more effectively between recycling and manufacturing.

This activity is also being translated into European projects. CIC energiGUNE participates in initiatives such as METALLICO, focused on recovering battery metals from primary and secondary resources; M-BAT, aimed at recovering battery-grade materials through innovative technologies; and SUCCESSOR, focused on sustainable processes associated with new generations of LMFP materials.