From Kitchen Drawer to EV Battery: The Cobalt Loop

The Metal Sitting in Your Kitchen Drawer Right Now

There are an estimated 55 million unused mobile phones gathering dust in UK homes, according to research from Material Focus. That's not just wasted cash - it's a warehouse of critical materials that two of the UK's biggest industries are actively competing for.

One of those materials is cobalt. It's in the lithium-ion battery of your old Samsung Galaxy S24. It's also in the battery pack of a new Tesla Model Y sitting on a forecourt in Solihull. The connection between those two objects is more direct than most people realise - and understanding it makes the case for recycling your phone more compelling than any guilt trip about landfill ever could.

We see this every day at OnRecycle. People check what their old phone is worth, pocket the cash and move on. Brilliant. But the material story that starts the moment that phone reaches a recycler is genuinely remarkable, and we think it deserves telling properly.

How Much Cobalt Is Actually in Your Phone?

A typical modern smartphone contains roughly 5-15 grams of cobalt, most of it locked inside the lithium-cobalt-oxide cathode of the battery. The Samsung Galaxy S24, one of the most-recycled phones we see through our platform right now, sits at the lower end of that range - around 6-8 grams, thanks to Samsung's shift toward lower-cobalt NMC (nickel-manganese-cobalt) chemistry in recent years.

That sounds tiny. It is tiny. But scale matters enormously here.

A single EV battery pack - say, the 75 kWh unit in a standard-range Tesla Model 3 - contains somewhere in the region of 4.5 to 7 kg of cobalt depending on the cell chemistry used. Do the maths on that. At 7 grams per handset, you'd need roughly 650 to 1,000 smartphones to yield enough cobalt for a single EV battery pack, accounting for recovery losses in the smelting process.

That's not a hypothetical. The UK registered over 380,000 new battery electric vehicles in 2025, according to the Society of Motor Manufacturers and Traders. The cobalt demand that represents is staggering - and the Democratic Republic of Congo, which supplies around 70% of the world's mined cobalt, cannot be the only answer to that demand forever.

The Journey: From Recycler to Refinery to Battery Cell

So what actually happens after your old phone reaches a recycler? The process is more sophisticated than most people imagine, and the cobalt recovery chain has tightened considerably over the last five years.

Step one is sorting and disassembly. Reputable UK recyclers - the kind we partner with on our platform - grade and test incoming devices. Phones that can be refurbished are refurbished. The rest are stripped of their batteries before shredding, because puncturing a lithium battery mid-process creates serious fire and chemical hazards.

Those recovered batteries then go to specialist hydrometallurgical processors. In the UK, companies like Recyclus Group have invested heavily in this infrastructure. The batteries are shredded in inert atmospheres, producing what the industry calls "black mass" - a dark powder containing lithium, cobalt, nickel and manganese in recoverable concentrations.

Black mass is then processed through a series of acid leaching and solvent extraction steps. What emerges on the other side are battery-grade cobalt sulphate crystals, ready to re-enter the cathode manufacturing supply chain. From there, they travel - often to South Korea, Japan or increasingly to new UK gigafactories like the Envision AESC plant in Sunderland - where they're incorporated into fresh cathode material for new EV cells.

Your old Galaxy S24, in other words, could end up propelling a Nissan Leaf down the A1 within 18 months of you selling it.

Why the Cobalt Supply Problem Makes Your Old Phone More Valuable

Cobalt has a serious ethical and geopolitical problem. The majority of global supply comes from artisanal mines in the DRC, where human rights organisations including Amnesty International have documented child labour and dangerous working conditions for years. Battery manufacturers are under increasing pressure from the EU's Battery Regulation (which came into full effect in 2024) to demonstrate due diligence across their entire cobalt supply chain.

Recycled cobalt sidesteps that problem entirely. It has a clean, traceable provenance. It requires no new mining. And according to a 2023 lifecycle analysis by the Faraday Institution, producing cobalt from recycled batteries generates roughly 80% less CO2 than extracting it from virgin ore.

That's why demand for black mass from UK-sourced consumer electronics is genuinely increasing. Battery manufacturers and their tier-one suppliers are actively seeking out recycled feedstock - not just for ethical reasons, but because incoming EU regulations will require a minimum percentage of recycled content in new EV batteries by 2030.

This shifts the dynamic. Your old phone isn't just an inconvenient piece of e-waste. It's a source of conflict-free, low-carbon cobalt that the EV industry needs. That's a fundamentally different way of thinking about the device sitting in your kitchen drawer.

What Your Old Phone Is Worth Right Now

Here's where the environmental story connects to something immediately practical. The best time to sell your phone is before its value drops further - and most phones lose value faster than people realise.

From our current data, a Samsung Galaxy S24 in good condition fetches up to £174 through the recyclers on our platform. An iPhone 15 Pro Max 256GB still commands strong prices. Even older models that feel worthless often aren't - we regularly see people surprised by quotes for three and four-year-old handsets they assumed had zero resale value.

The cobalt and other materials inside those phones have real, quantifiable worth to the supply chain. Recyclers are essentially paying you a share of that material value, plus the refurbishment premium where applicable. That's why prices from specialist phone recyclers consistently beat what you'd get from a high street trade-in programme at a network store.

Our data shows the spread between the best and worst quotes for the same device can be £40 to £80 on a mid-range handset. That's real money left on the table if you don't compare properly.

The Phones We See Most — and What Happens to Them

From the volume of devices sold through our platform, Samsung Galaxy S-series and iPhone models make up the bulk of what UK consumers recycle. The Samsung Galaxy S24, iPhone 14 series and iPhone 13 are consistently in our top ten most-recycled handsets month after month.

The good news is that these are exactly the handsets recyclers most want. High-volume, well-documented battery chemistry, reliable disassembly pathways. They're the workhorses of the black mass supply chain.

Phones in worse condition - cracked screens, faulty charging ports, water damage - still have significant material value even when they can't be refurbished. A non-working Samsung Galaxy S24 still contains that 6-8 grams of cobalt, plus copper, gold, silver and rare earth elements. Recyclers will still pay for them, just at a lower rate reflecting the absence of refurbishment premium.

The worst outcome, by a long way, is leaving the phone in a drawer. Or worse, putting it in a general waste bin, where it ends up in landfill. Cobalt in landfill doesn't stay inert - it leaches into soil and groundwater over time, creating environmental contamination while simultaneously being unavailable for the EV battery supply chain that desperately needs it. That's a lose-lose that's entirely avoidable.

Close the Loop: What to Do Today

The cobalt loop only works if enough people close it. Right now, with 55 million unused phones in UK homes, the loop is wide open - materials are sitting idle instead of cycling back into the clean energy economy.

The practical step is simple. Take whatever old phone is gathering dust - whether it's a Samsung Galaxy S24, an iPhone 12 or a three-year-old Google Pixel - and get a quote today. It takes about 90 seconds. You'll see real prices from real recyclers, ranked so the best offer is at the top. No obligation, no faff.

You might be surprised what it's worth. And even if the number is modest, you'll be doing something that matters - sending conflict-free cobalt back into the supply chain for the next generation of electric vehicles, instead of leaving it to corrode in a kitchen drawer. That's not a small thing. That's the circular economy actually working.

For more guides on getting the best price for your devices, check out our blog - we cover everything from timing your sale to understanding recycler grades.

Published by The OnRecycle Team on 10th March 2026