All-in-one structured textile energy storage electrodes prepared via Janus bond assembly-induced electrodeposition

One of the most critical issues in developing high-performance textile-based energy storage (TES) electrodes is to effectively incorporate conductive and electrochemically active components into insulating textiles, maintaining the high mechanical flexibility and large surface area of pristine textiles. Herein, we report a high-performance TES electrode prepared from a Janus bond assembly of nonnoble metal-based nanoparticles (NPs) and subsequent electrodeposition. First, tetraoctylammonium-stabilized copper sulfide NPs (TOA-Cu_xS NPs) with a diameter of ∼10 nm were synthesized in organic media, which were Janus bond layer-by-layer (JB LbL)-assembled with cysteamine (CA) linkers onto cotton textiles. In this case, CA linkers directly and robustly bridged all the interfaces between the OH-functionalized textile and Cu_xS NPs as well as between neighboring Cu_xS NPs. Additionally, the JB LbL-assembled Cu_xS NPs perfectly converted the insulating textile to a conductive textile with a uniform fibril structure and oxidation stability. For the preparation of pseudocapacitive textiles, the subsequent Ni electrodeposition was further carried out onto the conductive and hydrophilic (TOA-Cu_xS NP/CA)_n multilayer-coated textile. The formed TES electrodes exhibited a low sheet resistance of 0.03 Ω sq⁻¹, a highly uniform fibril structure, a considerably high areal capacitance of 2.56 F cm⁻² (at 3 mA cm⁻²), and high operational stability (i.e., capacity retention of 88.6 % after 10,000 cycles).