Hydrated LiOH modified Ni_0.1Fe_0.9PS₃ anodes towards safer high-performance lithium-ion batteries

Direct contact pre-lithiation with additives in anodes brings a potential strategy for developing highly cyclable lithium ion batteries (LIBs). Herein, using hydrated LiOH as an additive having multifunctional roles, applications of Ni-doped FePS₃ (Ni_0.1Fe_0.9PS₃) layers are theoretically and experimentally demonstrated for high capacity and cyclability LIBs. It is shown that the aggregation of Li₂S, affecting reversibility of chalcogenide-based anodes while hosting lithium ions in the reversible intercalation process, can be addressed by weakening the bond polarizability in Fe-S bond with LiOH addition. This improves the cyclability and rate retention along with a higher capacity, evincing hydrated LiOH as a safer pre-lithiation agent – unlike many other reported additives. The calculated density of states of pre-lithiated Ni_0.1Fe_0.9PS₃ reveals the development of new symmetric point that is beneficial for achieving high electrical conductivity along with a higher binding energy for Li. The results underline the improved capacity with modification (524 mAh g⁻¹ at 1 A g⁻¹ after 100 cycles) than with that of unmodified one, in tune with the experimental results. This demonstration hence establishes a new safer generic strategy for developing high-rate retention anodes of sulphides in next generation energy storage devices.