From a waste point of view one of the biggest changes over the past fifteen years has been the huge expansion of the market for lithium-based batteries, with the most common type being rechargeable lithium ion cells. Until the mid-1990s the most common use for these was in specialist camera batteries but now they’re become ubiquitous. Cellphones, laptop and tablet computers, almost all modern MP3 and media players, and increasingly flashlights and similar devices – they’re all powered by lithium ion batteries.
In many ways this unfortunate, because as far as recycling is concerned these batteries are a challenge. The materials they contain have little economic value so recycling them is not profitable, but disposing of them in landfill is an unacceptable risk. As they deteriorate they can release toxic lithium compounds into the environment; if they hold a residual charge when disposed of they can even suffer from thermal runaway, which often results in a fire. Fires in landfill sites can burn underground for years and often do considerable damage.
The problem of lithium-ion batteries is a significant one now, but over the next few years it could become a whole lot worse. There’s a lot of pressure to move to electric cars and these use lithium ion batteries too – and in a much more powerful, and bulkier, form. Right now the number of electric cars on the road can be measured in the thousands, and the disposal of old batteries from them isn’t a significant issue, but what about when there are tens of millions of them? Even with the very high energy density of L-Ion batteries – the characteristic that’s made them so widely used – the batteries in an electric car weigh hundreds of pounds, and they don’t have an unlimited life. After several hundred charge cycles they begin to lose capacity and need to be replaced. The old ones go for (uneconomical) recycling or (unsafe) disposal.
There are alternatives when it comes to car batteries, however. Even after they drop below the minimum specification for automotive use they can hold a substantial charge and can be repurposed; Mineta National Transit Research Consortium estimate up to 85 percent of them can be reused. It’s also often possible to test the individual cells and replace the most degraded ones, bringing the battery back up to a usable storage level.
The volume of batteries generated by widespread electric car use will be far too large for landfill disposal to be a viable option, and straightforward recycling would add substantially to costs. However if repurposing and refurbishment plants start to open recycling could be run more economically alongside those processes, and that has obvious benefits. With the infrastructure to safely process spent lithium cells in place it could easily be used beyond the car battery sector, to deal with the large number contained in obsolete electronic devices. Lithium batteries have the major environmental benefit of allowing electricity from renewable sources to be used in portable devices or even for propulsion, but to achieve the full benefits the lifecycle of the batteries themselves needs to be better managed.