According to the Japan Advanced Institute of Science and Technology (JAIST) researchers, widely used graphite anodes are mostly to blame for lithium-ion battery life degradation. The team, led by professor Noriyoshi Matsumi, released its latest findings in the ACS Applied Energy Materials journal on February 17.
The inevitable degradation of these rechargeable batteries has been one of the main stumbling blocks in renewable energy harvesting and more significant investments into the electric vehicle industry. It is also the primary reason for the limited lifetime of portable electronic devices, which is why researchers worldwide have been perfecting the lithium-ion design for decades.
The team at JAIST believes that the negative terminals in batteries are to blame. The graphite anodes, together with cathodes (positive terminals) and the electrolyte (the charge holder), provide the setup for the process of charging and discharging the battery. Unfortunately, graphite anodes require a binder to prevent them from degrading with use, and the current solution, polyvinylidene fluoride (PVDF), is far from ideal.
Therefore, the researchers at JAIST have come up with an alternative solution for the graphite anode binders. Instead of using polyvinylidene fluoride, they conducted the experiments using a bis-imino-acenaphthenequinone-paraphenylene (BP) copolymer.
The results speak for themselves: according to the paper, a traditional PVDF binder helped the battery retain only 65% of its original capacity after just 500 charge and discharge cycles. In comparison, a BP copolymer used as a binder provided a 95% battery life retention after as many as 1,700 complete charge-discharge cycles.
These findings are set to revolutionize the development of long-lasting Li-ion batteries. In the words of professor Matsumi: “The realization of durable batteries will help in the development of more reliable products for long-term use. This will encourage consumers to purchase more expensive battery-based assets like electric vehicles, which will be used for many years.”
In addition to reducing environmental pollution, longer-lasting batteries will provide more durable smart devices and pave the way to further advancements in medical technologies such as artificial organs. This will doubtlessly have long-term effects on the global economy and hopefully lead us into a cleaner, more eco-friendly future.