Lithium-ion battery with high-voltage LiNi0.5-xFexMn1.5O4/pectin electrode material

Cobalt-free LiNi_0.5Mn_1.5O₄ (LNMO) is widely recognized as a promising cathode material for lithium-ion batteries because of its cost-effectiveness, environmental sustainability, and the ability to achieve a discharge voltage platform close to 5 V. In this work, we conducted a comprehensive investigation into the material properties and electrochemical characteristics of LNMO and various levels of iron-doped LiNi_0.5-xFe_xMn_1.5O₄ (LNFMO) (with x values of 0.08, 0.10 and 0.12). In the pursuit of enhancing environmental sustainability and advancing green energy storage technology, eco-friendly pectin was used as a binder instead of traditional polyvinylidene fluoride (PVDF). LiNi_0.4Fe_0.1Mn_1.5O₄ (LNFMO-0.10), devoid of Li_xNi_1-xO impurity phases, demonstrated exceptional performance. After 100 cycles at a 0.1C-rate, the discharge specific capacity remained at 111 mAh·g⁻¹, with a capacity retention of 96 %. Moreover, the pectin binder, which is water-soluble, made it possible using a simple process with deionized water to recycle LNMO and LNFMO-0.10 cathode materials. SEM images reveal smaller particles in recycled LNFMO-0.10, due to particle fracture during cycling. XRD patterns confirm the persistence of the spinel phase in the recovered material, though with slightly reduction in specific capacity due the loss of lithium content.