Anode-less thin-film battery with Sn/C layer: 235.13 Wh/L

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 doi.org. The cathode was a 2-µm-thick lithiated vanadium oxide (LVO) film. The work is a laboratory study of thin-film cells. doi.org

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. doi.org The weak point is lithium loss through interphase formation, electrically isolated "dead" lithium and loss of contact with the solid electrolyte during stripping. doi.org

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. doi.org 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. doi.org

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. doi.org

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. doi.org

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. doi.org

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. doi.org

Dongguk University: anode-less thin-film cell with a Sn/C layer reaches 235.13 Wh/L at cycle 100

Sn/C seed layer

Prelithiation and results

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