A new, sustainable, recycling technology is developed for the first time by reusing all the components of spent LIBs (anode, cathode, separator, and current collectors) towards energy storage, conversion, and harvesting applications, considering the environmental concerns and valuable resources. The graphite anode and metallic aluminium cases are effectively recycled to produce two-dimensional graphene sheets that are reutilized for 3.0 V supercapacitors exhibit a high energy density of 31.9 Wh kg–1 with long cycle life. The spent cathode is regenerated as Ni–Mn–Co–oxide and employed as a novel bifunctional electrocatalyst for overall water splitting in alkaline electrolytes, which requires a low voltage of 1.58 V to achieve a current density of 10 mA cm−2. The metallic current collectors and polymeric separator are reused to construct a triboelectric nanogenerator, produces a maximum voltage of ~40 V and a current of ~160 nA with a peak power of 3 μW. Hence, this study provides a feasible strategy of recycling all the components from spent LIBs to develop next-generation energy storage, conversion, and harvesting devices.