MoS ₂ protected LiAl intermetallic compound Li metal anode exhibits a highly reversible Li migration for lithium metal batteries.

Zn ₂ GeO ₄ and Zn ₂ SnO ₄ nanowires showed an excellent cycling performance for both lithium- and sodium-ion batteries.

Germanium sulfide (GeS and GeS₂) nanoparticles were synthesized by novel gas-phase laser photolysis and subsequent thermal annealing. They showed excellent cycling performance for lithium ion batteries, with a maximum capacity of 1010 mA h g⁻¹ after 100 cycles. Metastable tetragonal phase Ge nanoparticles were suggested as active materials for a reversible lithium insertion–extraction process.

Germanium–tin (Ge_1−xSn_x) alloy nanocrystals were synthesized using a gas-phase laser photolysis reaction of tetramethyl germanium and tetramethyl tin. A composition tuning was achieved using the partial pressure of precursors in a closed reactor. For x < 0.1, cubic phase alloy nanocrystals were exclusively produced without separation of the tetragonal phase Sn metal. In the range of x = 0.1–0.4, unique Ge_1−xSn_x–Sn alloy–metal hetero-junction nanocrystals were synthesized, where the Sn metal domain becomes dominant with x. Thin graphitic carbon layers usually sheathed the nanocrystals. We investigated the composition-dependent electrochemical properties of these nanocrystals as anode materials of lithium ion batteries. Incorporation of Sn (x = 0.05) significantly increased the capacities (1010 mA h g⁻¹ after 50 cycles) and rate capabilities, which promises excellent electrode materials for the development of high-performance lithium batteries.

We report arsenic (As) as a promising alternative to graphite anode materials in lithium- and sodium-ion batteries (LIBs and SIBs). The electrochemical properties of the As/carbon nanocomposite for both LIBs and SIBs were investigated using experimental and theoretical approaches. The LIBs showed excellent cycling performance, with a reversible capacity of 1306 mA h g⁻¹ (after 100 cycles), which is much higher than that of Li₃As (1072 mA h g⁻¹). In the corresponding SIBs, the measured reversible capacity was 750 mA h g⁻¹ (after 200 cycles), which is lower than that of Na₃As. Extensive first-principles calculations were performed employing a structure prediction method for crystalline Li_xAs and Na_xAs (x = 1–6) phases, as well as ab initio molecular dynamics simulations for their amorphous phases. In good agreement with the experimental LIB data, our calculations successfully predict the discharge capacity versus voltage curves, showing that the capacity of the amorphous phase reaches up to that of Li₄As. In contrast, the SIB exhibited difficulty in reaching the predicted capacity (x = 3.5), probably due to significant volume expansion. Comparison of the theoretical discharge curves with the experimental data provides valuable information for the development of high-performance LIBs and SIBs.