A surface-nitridized 3D nickel host for lithium metal anodes with long cycling life at a high rate

Three dimensional (3D) metal structures such as nickel (Ni) and copper (Cu) frames have long been regarded as a good host for lithium (Li) metal. However, Li deposition on different metals often causes obvious over-potential, affecting the electrode performance in lithium metal batteries. Here, a Ni-N-O interface was created by surface nitridation to the Ni micro-particles, which were made into 3D current collectors. The directly grown Ni₃N created a thin and lithiophilic layer containing dense Li nucleation sites. The homogeneous distribution of amorphous Ni₃N and NiO at the interface allowed for a fast transfer of both electrons and ions, and thus facilitated smooth and even plating/stripping of lithium. High cycling stability and rate capability were simultaneously achieved. The 3D Li@N-Ni anode exhibited an extremely low voltage hysteresis of ∼10 mV over 850 h in a symmetric cell. The full battery paired with LiFePO₄ achieved steady cycling at 5C for 1500 cycles, with coulombic efficiency constantly higher than 99.2% and an average capacity loss of 0.027 mA h g^-1 per cycle, demonstrating a rational strategy for the design and fabrication of efficient lithium anodes for practical applications.