Probably a lot more energy is needed to produce more electronics and batteries for hybrid vehicles due to research & development (R&D). I do not know the statistics but in this link => http://www.hybridcars.com/battery-toxicity.html, they say it's in the millions of dollars. The toxicity of any type of battery of any vehicle varies. The article says that the Environmental Defense compared commonly used batteries and concluded lead (more traditionally used in non hybrid vehicles) was the worst, then nickel,and lithium (used more in hybrid vehicles) was the least damaging to the environment. Companies like Honda and Toyota are also thinking ahead with their programs to recycle these new lithium ion batteries and parts for hybrid cars. The precious metals and plastics are either neutralized to reduce any hazards it may cause in the landfills or recycled and reused.