Solid state battery brings electric boat range
Extending the capacity of batteries is seen as the key to increasing the range and so promoting the viability of electric boats writes Dag Pike.
It appears that researchers at Samsung have come up with a potential solution with a solid state battery.
With the current batteries that are in use, which are mainly based on various types of lithium-ion, designers have to find a balance between the weight and size of the batteries and their capacity. It is the weight and size that limits the performance of the boat and is the main factor that limits the range. Most of the research on new types of battery is based around the requirements of the road vehicle sector which is potentially a huge market with the marine sector feeding off the back of road developments.
There are three basic parts of a battery, the positive cathode and the negative anode both of which sit in the electrolyte. In a lithium-ion battery the electrolyte is a lithium salt in a solvent and the electrodes are made out of various solid substances with carbon and metal tending to be favoured. With a solid state battery the electrolyte is a solid and because these are denser than liquids, it means the battery can have a higher energy density, in other words it can store more energy for the same volume, which tends to be the Holy Grail of battery development.
Researchers at the Samsung Advanced Institute of Technology were looking into using a silver carbon composite layer as the anode. The team found that by incorporating a very thin layer into a prototype cell, the battery could support a larger capacity combined with a longer cycle life and improved safety. This enabled them to make their prototype approximately 50% smaller by volume than current batteries.
The Samsung team is still faced with the challenge of translating this research into a workable model that can be manufactured economically and the obvious benefits of moving to a solid state battery like this means that Samsung is not the only team working along these lines. The quest for the ideal solid state battery means research teams all over the world are trying to figure out what the solid electrolyte should be and how it is used in combination with different anodes and cathodes. The solid battery breakthrough is still some way off but the potential for this technology is becoming clearer.
