Unraveling and regulating electrode-electrolyte integration towards high-performing MoS2 loaded fiber shaped supercapacitor

Abstract

Molybdenum disulfide (MoS₂) is touted as a highly promising material for fiber-shaped supercapacitors (FSCs) but limited by its low capacitance and unsatisfactory cycling stability. Here, we report a MoS₂ deposited stainless steel wire (MoS₂@SSW) that can be electrochemically intercalated with dual ions (Na⁺ and H⁺). A high capacitance of ∼1632.7 mF cm⁻² at 0.4 mA cm⁻² and high capacitance retention of 84.25 % after 10,000 cycles under sulfuric acid/sodium sulfate (H₂SO₄/Na₂SO₄) aqueous electrolyte is recorded for this system. This is mainly attributed to the pre-intercalation of H⁺ into MoS₂ to form MoS-SH. This process redistributes the local charge regions on MoS₂ surface and lowers the energy barrier for Na⁺ migration in MoS₂ to facilitate the adsorption and intercalation of Na⁺. Notably, MoS₂@SSW FSCs are integrated into three-dimensional space textiles as a proof-of-concept. This novel exploration of the nanointerface resulted by electrolyte engineering offers a feasible design paradigm for the development of high-performing FSCs.