Looks like 3 basic problems need to be solved before electricity takes over from petrol and diesel.
 

Problem One:

Batteries are too big and heavy, which means size and weight limit the number of batteries that can be installed in an electrical vehicle. The up market Tesla Model S for example, has a battery pack approximately 2 meters long by 1.2 meters wide, which is installed flat along the floor of the car. In their top-spec car it gives a range of about 450 km before plugging in and recharging is required. The Nissan Leaf achieves more like 120-130 km’s before recharging.

Problem Two:

Recharging is too slow and as your charge runs out you need to plug in somewhere. If you run out away from home or a recharge station then I guess it’s just like running out of petrol. Recharging your batteries is getting quicker depending on the type of battery but still can take from 1 to 8 hours to fully recharge. Hopeless if you need to be somewhere quickly. (Can’t see many would wait that long to full the tank with petrol).

Problem Three:

Batteries are too expensive, all batteries even the rechargeable kind have a limited life span so they will need to be replaced at some stage. You will have to keep in mind the balance between cost and convenience when considering a vehicle where the electricity is stored in batteries that powers your car. Maybe a lease or rental plan for your batteries would be a wise idea.

Are batteries getting better?

Basically yes they are improving, a battery contains a positive and negative electrode, a separator and an electrolyte. Many different types of materials can be used as electrodes, the different combinations of materials allowing different amounts of energy to be stored with different results.

 
However battery life and the safety characteristics change as these materials that are used vary. A compromise is always necessary. Lithium-ion batteries are popular currently, but have been associated with fires and their transport is restricted. Anything more reactive or unstable could be a hazard. Once they get the material combination right the payoff will be great.
 
There has been a long line of improvements over the years. First we had lead-acid car batteries, still used in conventional vehicles. Then came rechargeable NiCad batteries found in laptops, phones and remote control cars. Next came NiMH batteries, with about twice the capacity, or energy density. Now lithium ion, or Li-ion, batteries power modern devices like smart phones, tablets and are found in the electric cars we are seeing today.
 
The next generation of battery technology will have increasingly complicated names like the LiNiMnCo (lithium–nickel-manganese-cobalt-oxides) battery. The materials have complex properties, and work is now going on to figure out not only why these materials work, but exactly how they work with the basic physics of the electrons moving around these materials.
 
Yet another development is the lithium-air, lithium-oxygen and the lithium-sulphur batteries. These batteries, if they can be made to work, under all possible conditions, will be a huge improvement over the current Li-ion batteries. So there is a lot of work going on with battery technology, however there are a lot of problems to solve at the same time.

Labs around the world are working on the problem, trying to overcome the drawbacks. The hope is that greater importance is placed on these next generation technologies to ensure faster progress in their development, and in the long-run faster cars that travel longer distances.

It’s simple really batteries that are light, small, cheap and take 2 minutes to recharge, no problem!

December 2014