Heterogeneous Engineering Strategy Derived In Situ Carbon-Encased Nickel Selenides Enabling Superior LIBs/SIBs with High Thermal Safety.

Nowadays, the extended usage of lithium/sodium ion batteries (LIBs/SIBs) encounters nerve-wracking issues, including a lack of suitable reservoirs and high thermal runaway hazards. Although using TiO and LiTiO has been confirmed to be effective in improving battery safety, their low theoretical capacities inevitably cause damage to the electrochemical performance of the battery. Achieving win-win results has become an urgent necessity. This study designed a metal-organic framework (MOF)-derived in situ carbon-coated metal selenide (Ni-Se@G@C) as the anode. When the current density is 0.1-0.3 A g, the initial capacity of LIBs reaches 993.2 mAh g, which increases to 1478.9 mAh g after running 800 cycles. When running at 2 A g, the cell also offers a relatively high capacity of 458.3 mAh g after 1500 cycles. After the replacement of graphite with Ni-Se@G@C, the self-heating temperature () and thermal runaway triggering temperature () of half and full cells are significantly increased. Meanwhile, the maximum thermal runaway temperature () and maximal heating release rate (HRR) are significantly reduced. Of note, the usage of Ni-Se@G@C enables the battery with superior cycling and rate performance. When used in SIBs, the cell gives an initial discharge capacity of 624.9 mAh g, which still remains at 269.4 mAh g after running 200 cycles at 1 A g. Notably, of the Ni-Se@G@C cell is 5.6 times higher than that of the graphite cell, corroborating the promoted safety performance. This work provides a new paradigm for MOF-derived micro/nanostructures, enabling the battery with an excellent electrochemical and safety performance portfolio.