New Scientist: Green machine is our weekly column on the latest advances in environmental technologies It’s a common complaint: we’d like to be greener, but the cost is exorbitant. When it comes to plug-in hybrids and all-electric cars, it’s an argument that has some justification “” largely because of the cost of the powerful lithium-ion batteries they run on. So how can we reduce the cost of batteries without curtailing their performance? Let’s rule out just waiting: battery costs are …