Carbonization‐free wood electrode with MXene‐reconstructed porous structure for all‐wood eco‐supercapacitors

Abstract To bypass the conventional high temperature carbonization, MXene with an ultra‐high electrical conductivity and good electrochemical activity is coated on natural wood to make it a free‐standing electrode (TW). TW achieves a high electrical conductivity of 106.4 S m⁻¹ and large capacitance of ~700 mF cm⁻² at 0.5 mA cm⁻². Furthermore, to overcome the low space utilization of the oversized vessels in wood which leads to a low energy density, a reconstructing strategy is used on TW to fully use the natural porous structure of wood by filling MXene aerogels in vessels. Compared with TW, the MXene aerogel‐loaded TW shows higher electrical conductivity of 323.6 S m⁻¹ and capacitance of 930 mF cm⁻² with remarkably high rate capability of 88.2% (0.5–10 mA cm⁻²). Additionally, an all‐wood eco‐supercapacitor is fabricated, and achieves a high energy density of 23 μW h cm⁻² at 577 μW cm⁻². image