Bilayer artificial interface engineering enables dendrite-free and low-temperature stable lithium metal batteries

Rational design of lithium (Li) metal anodes is critical for achieving uniform Li deposition and long-term cycling stability. Here, we report a sequential atomic layer deposition of lithiophilic ZnO and Li₂O coatings on 3D carbon paper to construct a vertically graded bilayer artificial interface. The underlying ZnO-derived LiZn/Li₂O domains act as mixed ionic/electronic conductors and provide stable nucleation sites for Li deposition. The high-resistance Li₂O top layer suppresses electron tunneling and increases the nucleation size. This synergistic design directs bottom-up Li growth, fully exploiting the internal voids of the 3D scaffold, suppressing dendrite formation. As a result, the Li@CP/Z6L1||LCO cell achieves 83.1 % capacity retention after 200 cycles at −20 °C (∼4000 h), while the Li@CP/Z6L1||LFP cell maintains 96.4 % capacity after 500 cycles, with only 0.0072 % capacity loss per cycle. This work demonstrates a rational bilayer interface design that leverages vertical conductivity gradients and interfacial chemistry to achieve high-performance, durable, and low-temperature-tolerant lithium metal anodes.