All-Electrochem-Active Graphite Electrode Enabled by Manipulating Li⁺ Activity of Inactive Components for High-Energy...

Graphite anodes have approached their theoretical specific capacity of 372 mA h g^-1, which becomes an obstacle for further increasing the energy density of commercial lithium-ion batteries. Various strategies have been proposed to enhance the energy density of graphite-based full batteries, such as decreasing the usage of inactive binders and conductive additives and exploring graphite/SiO _x composite anodes. Nevertheless, the anodes cannot balance energy density, power density, and cycling stability. In this study, we designed an all-electrochem-active graphite electrode by manipulating the Li⁺ activity of the inactive components to improve the energy density of the entire electrode. In our study, colloidal two-dimensional titanium carbide nanosheets (MXene) were employed as binders, and carbon-coated titanium dioxide nanoparticles with oxygen defects (TiO_2-x @C) acted as conductive additives in the electrode configurations. Both MXene and TiO_2-x @C can function as active materials to store lithium ions by reversible insertion and extraction with little electrochemical degradation. As a result, the all-electrochem-active graphite electrodes demonstrated a superior specific capacity of 394 mA h g^-1 at a current density of 0.2C after 300 cycles. This concept of all-electrochem-active electrodes is anticipated to inspire future research on high-energy-density batteries by activating the Li⁺ affinities of binders and conductive additives.