In a new study, researchers have developed a new technology to produce longer-lasting lithium batteries.
The research was conducted by a Columbia Engineering team.
Battery has become an important energy source for humans because we rely on it on everything from portable devices to electric vehicles.
However, it is hard to improve energy storage and increase battery life while ensuring safe operation.
To solve the problem, in the new study, the team have developed a new method for safely prolonging battery life.
They insert a nano-coating of boron nitride (BN) to stabilize solid electrolytes in lithium metal batteries.
Conventional lithium-ion (Li-ion) batteries are widely used in daily life, but they have low energy density and thus shorter battery life.
Because they contain a highly flammable liquid electrolyte, they can short out and even catch fire.
Previous research has shown that energy density could be improved by using lithium metal to replace the graphite anode.
But this method can cause short-circuits and lower battery safety.
In the study, the team focused on solid, ceramic electrolytes.
The materials show great promise in improving both safety and energy density.
This is because most solid electrolytes are ceramic, and therefore non-flammable and safer.
In addition, solid ceramic electrolytes have a high mechanical strength that can actually suppress lithium dendrite growth.
The researchers deposited 5~10 nm boron nitride (BN) nano-film as a protective layer to isolate the electrical contact between lithium metal and the ionic conductor (the solid electrolyte).
They selected BN as a protective layer, which is only 5~10 nm thick, without lowering the energy density of batteries.
The material can work as a barrier to prevent the invasion of lithium metal to solid electrolyte.
The team also has developed a lithium-metal-proof ‘vest’ for unstable solid electrolytes. It can achieve long cycling lifetime lithium metal batteries.
Currently, the team is extending its method to a broad range of unstable solid electrolytes and further optimize the interface.
The leader of the study is Yuan Yang, assistant professor of materials science and engineering.
The study is published in Joule.
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