Sri Lanka is gearing up to create a $1.5 billion graphene-based lead-acid battery industry in the country using its abundant supply of vein graphite.
Associated Battery Manufacturers Ceylon (ABM) has agreed to purchase 50% of Ceylon Graphene Technologies’ (CGT) monthly graphene output, its chief executive Manju Gunawardana told a press conference last month.
CGT developed a graphene applied lead-acid battery with ABM last year. The technology uses mixed composites of reduced graphene oxide and expanded graphite to increase charge acceptance while reducing sulfation in negative plates.
The technology is due to be applied to Exide’s 2020 lead-acid battery range.
Graphene in a lead-acid battery improves conductivity, lowers resistance, increases cycle life and prevents sulphation in partial-state-of-charge more effectively than other forms of carbon. However, it’s expensive and primarily used in high-end products.
The graphene supply will come from output from CGT— a joint venture between Sri Lanka Institute of Nanotechnology (15% ownership) and LOLC Group (85%). Its plant will convert vein graphite into graphene when commissioned in April.
LOLC holds a 38.5% stake in ABM through its subsidiary Browns & Company while Exide Industries holds the majority stake of 61.5%.
CGT is due to initially produce 3.6 tonnes of graphene from graphite sourced from Kahatagaha, Bogala and Ragedara mines through LOLC Geo Technologies, a LOLC unit.
Dr Mike McDonagh explains how the use of graphene in lead-acid is not the same as in lithium-ion where it is an electrode.
As far as I know, it is used exclusively as an additive, in a similar way to graphite or carbon.
It enhances the performance of the active material due to its superior electrical conduction and beneficial effect on re-precipitation of lead from PbSO4 in the negative plate.
In summary, it improves conductivity, lowers resistance, increases cycle life and prevents sulphation in PSoC cycling more effectively than other forms of carbon.
It is very expensive and Chowei in China claim to use graphene in their black gold lead-acid battery to provide a 52% reduction in internal resistance.
There is a range of claims made for it’s effectiveness in improving lead-acid battery performance, these range from 50 to 300% depending on which battery characteristic is being measured and who is making the claims. Very little noise from battery manufacturers, it’s mostly the producers like Black Diamond making the claims.
It’s highly probable that it will significantly enhance lead-acid battery performance but not sure by how much. However, the batteries will be more expensive and not sure of the commercial viability due to the cost.
However, no-one would be idiotic enough to splash out many millions to build a factory without doing due diligence on market and technology before starting.