Samsung unveils solid-state lithium metal batteries
Samsung unveiled a solid-state battery that combines high energy density (942 Wh/L) with long cycle life (1.000 cycles). The study was published in one of the world’s leading scientific journals, the Nature Energy.
This pouch battery cell uses a solid electrolyte and a lithium metal anode (silver-carbon composite layer), which differentiates it from current mainstream batteries that use liquid electrolytes and graphite/silicon anodes.
Most recent battery technology advances have been achieved by improving the cathodes. It’s nice to finally see some solid advancements made in the anode and electrolyte fronts.
Let’s see the press release.
On March 9 in London, researchers from the Samsung Advanced Institute of Technology (SAIT) and the Samsung R&D Institute Japan (SRJ) presented a study on high-performance, long-lasting all-solid-state batteries to Nature Energy, one of the world’s leading scientific journals.
Compared to widely used lithium-ion batteries, which utilize liquid electrolytes, all-solid-state batteries support greater energy density, which opens the door for larger capacities, and utilize solid electrolytes, which are demonstrably safer. However, the lithium metal anodes that are frequently used in all-solid-state batteries, are prone to trigger the growth of dendrites1 which can produce undesirable side effects that reduce a battery’s lifespan and safety.
To overcome those effects, Samsung’s researchers proposed utilizing, for the first time, a silver-carbon (Ag-C) composite layer as the anode. The team found that incorporating an Ag-C layer into a prototype pouch cell enabled the battery to support a larger capacity, a longer cycle life, and enhanced its overall safety. Measuring just 5µm (micrometers) thick, the ultrathin Ag-C nanocomposite layer allowed the team to reduce anode thickness and increase energy density up to 900Wh/L. It also enabled them to make their prototype approximately 50 percent smaller by volume than a conventional lithium-ion battery.
This promising research is expected to help drive the expansion of electric vehicles (EVs). The prototype pouch cell that the team developed would enable an EV to travel up to 800km on a single charge, and features a cycle life of over 1,000 charges.
As Dongmin Im, Master at SAIT’s Next Generation Battery Lab and the leader of the project explained, “The product of this study could be a seed technology for safer, high-performance batteries of the future. Going forward, we will continue to develop and refine all-solid-state battery materials and manufacturing technologies to help take EV battery innovation to the next level.”
The full study gives us more details than the press release.
- Cycle life: 95 % SoH after 600 cycles and 89 % SoH after 1.000 cycles
- Volumetric energy density: 942 Wh/L with potential to surpass 1.000 Wh/L
SoH (State of Health) is used to measure battery capacity retention.
With this kind of volumetric energy density the BMW i3, which currently uses NCM 622 battery cells from Samsung SDI, could get a 89,9 kWh battery and an approximate WLTP range of 660 km. It would still have a range of 627 km after 386.100 km [(660 + 627) / 2 x 600] and 587 km after 623.700 km [(660 + 587,4) / 2 x 1.000].
For this study Samsung used a NCM cathode, which is very common nowadays. However, solid electrolytes and lithium metal anodes can also be combined with cobalt-free cathodes, such as LFMP or LiFePO4 as we can see in other study.
Finally, it’s also great news that the solid-state battery technology seems to be closer to reach production than it was anticipated in 2016, as we can see from the battery cell roadmap below.
The way things are heading now, it seems that in the not so distant future we’ll get solid-state batteries with lithium metal anodes combined with high energy dense cathodes (NCMA) and cobalt-free cathodes (LFMP).
You can read the full article published at Nature Energy with the unlocked Sci-Hub link below.