A popular myth among detractors of hybrid and electric vehicles is that the energy and materials that go into making batteries far outweighs any good they do under ownership.

Batteries aren't as damaging as many suspect though, since so many of a battery's components can be recycled.

Honda is doing just that with the nickel-metal hydride batteries found in its hybrid vehicles.

Since the first Honda hybrid, the Insight launched in 1999, Honda has used nickel-metal hydride chemistry in its batteries. The company has only recently changed to lithium ion with the 2013 CR-Z and new Accord Hybrid, but it means there are plenty of old nickel batteries out there on the roads.

Honda has invented a new process to extract an oxide containing rare earth metals like nickel from old batteries.

Using molten salt electrolysis, Honda can extract rare earth metals with 99 percent purity--the same as ordinary traded, newly mined rare earth metals. Up to 80 percent of the metals found in a battery can be extracted, and it's suitable for re-use on the electrodes of other batteries. You can see Honda's process in the diagram below:

Honda's process for recycling nickel-metal hydride batteries

Honda's process for recycling nickel-metal hydride batteries

So far, Honda has been extracting the minerals from the batteries of 386 Honda hybrid vehicles declared unsuitable for sale after 2011's Japanese earthquake and tsunami.

In less extreme circumstances, Honda would extract nickel from the batteries of hybrids brought in to dealers for battery replacement--an infrequent occurence, as Honda owners have found.

Batteries are more recyclable than people think. Even the humble lead-acid car battery, found in any vehicle, is the most recycled product on the planet. And those in hybrids are lasting longer than many suspected too, with old Honda or Toyota hybrids often not requiring replacements until 200K-300K miles have passed.

And if you're still not convinced about the environmental impact of hybrid vehicles, consider this--the vast majority of a car's lifetime environmental impact comes from its use, not its manufacture.

Take care of the recycling of batteries, and that's just one fewer thing to worry about when driving your hybrid.


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