Advanced Matrixes for Binder-Free Nanostructured Electrodes in Lithium-Ion Batteries

Commercial lithium-ion batteries (LIBs), limited by their insufficient reversible capacity, short cyclability, and high cost, are facing ever-growing requirements for further increases in power capability, energy density, lifespan, and flexibility. The presence of insulating and electrochemically inactive binders in commercial LIB electrodes causes uneven active material distribution and poor contact of these materials with substrates, reducing battery performance. Thus, nanostructured electrodes with binder-free designs are developed and have numerous advantages including large surface area, robust adhesion to substrates, high areal/specific capacity, fast electron/ion transfer, and free space for alleviating volume expansion, leading to superior battery performance. Herein, recent progress on different kinds of supporting matrixes including metals, carbonaceous materials, and polymers as well as other substrates for binder-free nanostructured electrodes in LIBs are summarized systematically. Furthermore, the potential applications of these binder-free nanostructured electrodes in practical full-cell-configuration LIBs, in particular fully flexible/stretchable LIBs, are outlined in detail. Finally, the future opportunities and challenges for such full-cell LIBs based on binder-free nanostructured electrodes are discussed.