Anode-Free Lithium Metal Battery Technologies

Anode-free lithium metal batteries employ a bare current collector as the negative electrode, onto which lithium is plated in situ from a lithiated positive electrode during initial charging. This configuration maximises energy density by eliminating excess lithium metal and its host matrix, reducing both cell weight and volume. The absence of a pre-deposited anode also simplifies manufacturing and lowers material costs. However, the limited lithium inventory and the high reactivity of freshly plated lithium give rise to low Coulombic efficiency, unstable solid electrolyte interphase (SEI) formation and dendritic growth. Addressing these challenges has driven research into current collector engineering, electrolyte formulation and mechanical regulation, as well as the exploration of solid-state and quasi-solid-state systems. Recent advances focus on achieving uniform lithium nucleation, enhancing interfacial stability and extending cycle life under lean-electrolyte and lean-lithium conditions, with a view to practical, high-energy applications in electric vehicles and grid storage.

Research from Nature Portfolio

Recent studies have elucidated the origins of irreversible capacity loss by developing integrated testing protocols that distinguish between SEI formation, dead lithium and other parasitic reactions, thereby guiding targeted improvements in cell design. Another investigation introduced an atomically defective carbon current collector, where engineered multivacancy sites promote homogeneous SEI formation and uniform lithium nucleation, resulting in a dense lithium layer and retention of over 90 % capacity after 50 cycles under lean-electrolyte conditions. Further work has demonstrated that the electrical resistance of the substrate can be tuned via ultrathin oxide or conductive nanofilms: highly resistive coatings direct lateral growth of large planar lithium deposits with low surface area, reducing side reactions and achieving up to a ten-fold enhancement in cycle stability.

Anode-Free Lithium Metal Battery Technologies publication trend

The graph below shows the total number of articles in anode-free lithium metal battery technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Anode-free lithium metal battery: cell configuration in which the negative electrode is a bare current collector that hosts lithium plated from the cathode during initial charge.

Coulombic efficiency: ratio of the charge extracted to the charge inserted in a battery cycle, reflecting reversibility of plating and stripping.

Solid electrolyte interphase (SEI): passivation layer formed by electrolyte decomposition on the electrode surface, critical for stabilising lithium deposition.

Current collector: conductive substrate that supports electrode reactions and serves as the host for lithium deposition in anode-free cells.

Dendrite: filamentous lithium structure that can form during plating, risking short-circuiting and capacity loss.

References

1. Toward maximum energy density enabled by anode‐free lithium metal batteries: Recent progress and perspective. Exploration (2023).
2. Decoupling the origins of irreversible coulombic efficiency in anode-free lithium metal batteries. Nature Communications (2021).
3. An electron-deficient carbon current collector for anode-free Li-metal batteries. Nature Communications (2021).
4. Electrical resistance of the current collector controls lithium morphology. Nature Communications (2022).
5. Regulating Li electrodeposition by constructing Cu–Sn nanotube thin layer for reliable and robust anode‐free all‐solid‐state batteries. Carbon Energy (2024).
6. Exploring the Impact of Mechanical Pressure on the Performance of Anode-Free Lithium Metal Cells. Journal of The Electrochemical Society (2019).
7. Optimizing Current Collector Interfaces for Efficient “Anode‐Free” Lithium Metal Batteries. Advanced Functional Materials (2023).