Purdue University's nanochain electrodes increase battery capacity/shorten charging time

According to foreign media reports, the length of battery life in mobile phones, computers or electric cars depends on how much lithium ions can be stored in the negative electrode material of the battery. If the lithium ions in the battery are exhausted, no current can be generated to drive the device, and the device cannot be used.

However, existing materials with higher lithium-ion storage capacity are either too heavy or in the wrong shape to replace graphite, the electrode material currently used in batteries.

Now, scientists and engineers at Purdue University have come up with a way to recombine electrode materials and design new electrodes that could extend battery life, make batteries more stable and reduce charging times.

The study created a mesh structure called a "nanochain" made of antimony, a metal that reportedly enhances the rechargeability of lithium-ion batteries. The researchers compared these nanochain electrodes with graphite electrodes and found that when a coin-sized battery equipped with nanochain electrodes was charged for only 30 minutes, after 100 charge and discharge cycles, its lithium-ion capacity was twice that of a battery equipped with graphite electrodes.

Some commercial batteries already use carbon-metal composites similar to antimony metal anodes as electrodes, but because these materials absorb lithium ions, they expand to three times the size of graphite electrodes, making such batteries a safety hazard when charging.

Purdue University scientists linked small antimony particles into a nanochain shape to accommodate expansion by using compounds – reducing agents and nucleating agents. The special reducing agent used by the research team – ammonia borane – creates voids within the nanochains, allowing for some expansion and preventing electrode failure.

The research team applied ammonia borane to several different antimony compounds and found that only antimony amide produced a nanochain structure, and this nanochain structure allowed the battery's lithium ion capacity to remain stable after at least 100 charge and discharge cycles.

The researchers said that this battery design can also be used for larger batteries, and the team plans to test it in soft-pack batteries next. Perhaps in the future, batteries suitable for electric vehicles can be developed . (All pictures in the article are from the official website of Purdue University)