Way back, a decade or so ago, there was talk of a revised lead-acid battery where the two poles were on the opposite sides of the same plate. This could halve battery weight and size, the pundits said. Since then the excitement has cooled down, although research into bipolar batteries has continued. We review recent progress courtesy of Science Direct.
Sodium-Ion Batteries Feature in Bipolar Research
Calls for smaller and smaller electronics, practical electric cars, and non-flammable storage continue to stack up unanswered. Sodium-ion batteries may yet be part of the solution, but to date they can’t compete with lithium-ion. They would need to gain an edge in terms of energy density first, and if they were non-flammable so much the better.
Science Direct – see link below – reports how traditional unipolar batteries, with separate electrodes have inherent resistance that causes voltage drops. Therefore, they say there is a ‘dire need’ to develop an alternative contender with improved energy density, safety, environmental profile, and cost-efficient technology.
How this Technology Works in Practice
Bipolar batteries sometimes crop up in this conversation, since they hold promise to eliminate internal voltage drops in the system, and facilitate ion transfer as follows:
- Unipolar batteries coat different current collectors on their anodes and cathodes.
- However, the bipolar alternative relies on a single current collector plate.
- This arrangement does not require extra interconnections to raise the voltage.
- And so it simply delivers relatively higher density, and voltage, with low heat.
However, that’s not the end to bipolar battery benefits, if we could get a working model to market. Although a number of limitations are still holding designers back. These include electrolyte leakage and sealing issues according to Science Direct. Although some success has been reported with lead-acid, and lithium-ion batteries so let’s watch this with interest.
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