Dongguk University: anode-less thin-film cell with a Sn/C layer reaches 235.13 Wh/L at cycle 100
Korean researchers built a laboratory thin-film cell without a pre-installed anode. A tin/carbon layer on copper guides lithium deposition and limits lithium loss.
A research team led by Professor Hyun-Suk Kim at Dongguk University (South Korea) developed an anode-less thin-film battery platform. According to the paper in Advanced Energy Materials, published on August 19, 2026, the optimized full cell reached a volumetric energy density of 235.13 Wh/L at the 100th cycle wiley.com
Advanced Energy Materialswiley.comOpen source ↗. The cathode was a 2-µm-thick lithiated vanadium oxide (LVO) film. The work is a laboratory study of thin-film cells.
In an anode-less cell, no lithium anode is installed in advance. Lithium from the cathode deposits on a bare current collector during the first charge and forms the anode in situ, which raises the stack-level volumetric energy density. The weak point is lithium loss through interphase formation, electrically isolated "dead" lithium and loss of contact with the solid electrolyte during stripping.
Sn/C seed layer
The cell combines an LVO cathode, a lithium phosphorus oxynitride (LiPON) solid electrolyte and a modified current collector. The authors screened ultrathin coatings on the collector: carbon only, metal only, and metal/carbon bilayers with Au, Ag, Zn, Al and Sn. The Sn/C bilayer on copper performed best. It gave the lowest lithium nucleation overpotential, reduced voltage hysteresis, better galvanostatic stability and the most uniform lithium plating.
The team reports that the tin layer lowers the energy barrier of nucleation, while the carbon overlayer helps regulate lithium growth. During initial plating, a three-dimensionally textured Sn/Li–Sn region formed in the interlayer. According to the authors, it can accommodate volume and morphological changes in later cycles. wiley.com
Advanced Energy Materialswiley.comOpen source ↗
Prelithiation and results
To reduce first-cycle losses, the researchers added a reversed-structure prelithiation step. A thin metallic lithium layer is deposited on the seeded collector and serves as a lithium reservoir, enabling gradual activation and stable cycling.
The 235.13 Wh/L figure at the 100th cycle was reported at a rate of 0.01 C. The total thickness of the battery is 2.77 µm.
Professor Kim said the approach could support ultrathin batteries for wearable electronics, IoT sensors and medical devices. This is the authors' statement; the study itself reports results for thin-film laboratory cells. wiley.com
Advanced Energy Materialswiley.comOpen source ↗
