Anode‐Free Lithium Metal Battery Enabled by Oxygen‐Functionalized MWCNT and TiN Interlayer for Uniform Lithium Deposition

Why It Matters

The breakthrough addresses dendrite growth and rapid capacity fade, two primary barriers to commercializing high‑energy anode‑free lithium metal batteries, potentially unlocking safer, cheaper, and higher‑density storage for electric vehicles and grid applications.

Key Takeaways

• TiN nanoparticles create lithiophilic sites, lowering Li nucleation overpotential
• COOH‑functionalized MWCNTs form conductive network, reducing local current density
• Oxygen groups promote lithium salt dissociation, yielding LiF‑rich SEI
• Anode‑free Cu@TiN‑MWCNT||LFP cell retains 51.4% capacity after 80 cycles at 0.5 C
• Low N/P ratio of 2.1 enables 144 mAh g⁻¹ after 150 cycles at 3 C

Pulse Analysis

Anode‑free lithium metal batteries (AFLMBs) promise energy densities far beyond conventional lithium‑ion cells, but their adoption has been hampered by unstable lithium plating, dendrite formation, and rapid capacity loss. Traditional designs rely on a thick lithium metal anode, adding weight and cost while posing safety risks. By eliminating the anode and depositing lithium directly onto a current collector, manufacturers can reduce cell mass and simplify production, yet they must engineer interfaces that can tolerate high current fluxes without compromising cycle life.

The Cu@TiN‑MWCNT interlayer tackles these challenges through a two‑pronged materials strategy. TiN nanoparticles act as lithiophilic nucleation sites, dramatically cutting the overpotential required for lithium to begin plating. Simultaneously, multi‑walled carbon nanotubes functionalized with carboxyl groups create a high‑surface‑area, conductive scaffold that spreads current uniformly and accelerates ion transport. The oxygen‑rich functional groups also enhance lithium‑salt dissociation, fostering a LiF‑rich solid electrolyte interphase (SEI) that is both mechanically robust and chemically stable, suppressing dendritic growth.

Performance data underscore the commercial relevance of this approach. The anode‑free Cu@TiN‑MWCNT||LFP cell maintains over half its initial capacity after 80 cycles at a moderate 0.5 C rate and delivers 144 mAh g⁻¹ after 150 cycles at a demanding 3 C, with coulombic efficiencies above 98%. Such durability at low N/P ratios signals a viable pathway for high‑energy electric‑vehicle packs and stationary storage systems where weight and cost are critical. As the industry seeks to scale AFLMBs, the TiN‑MWCNT interlayer could become a cornerstone technology, prompting further research into scalable coating processes and integration with next‑generation electrolytes.