Sabatier effect based adsorption-desorption coordination via cationized chitosan for enhancing ion kinetics in zinc anodes

Interface engineering through a Sabatier effect-based adsorption–desorption coordination via cationized chitosan offers a promising approach to counteract dendritic growth, hydrogen evolution, and sluggish Zn2+ kinetics. The adsorption effect in zinc ion batteries is important for maintaining a balanced distribution of zinc ions and reducing dendrite formation. However, an excessive emphasis on the adsorption effect often neglects the desorption process of zinc ions, leading to a decrease in overall ion reaction kinetics. Herein, an adsorption–desorption synergic coating called CGP@Zn was systematically designed on zinc anodes to serve as both a Zn2+ adsorption and desorption regulator and a functional protective interface. The CGP@Zn coating exhibited zincophilic and negatively charged amino and hydroxy functional groups, which facilitated the transport of Zn2+ ions and repelled free SO42- anions. Moreover, the positively charged N+ component of the CGP@Zn coating exhibited a strong desorption effect, guaranteeing the voluble retransfer of Zn2+ and promoting intensive kinetics. Collaborating with the functional interface layer, the CGP@Zn anode demonstrated a significantly high ionic transfer number of 0.72. Furthermore, CGP@Zn symmetrical cells showed an impressive ultralong lifespan of over 5000 h with an extremely low polarization voltage of ≈80 mV at 1 mA cm−2 and 2 mAh cm−2. More encouragingly, the MnO2-based full batteries endowed with the CGP interface layer achieved a capacity of 206 mAh g -1 with a retention of 91.8 % over 500 cycles at 1C. This study offers a new perspective for designing high-performance aqueous batteries via coordination of adsorption–desorption.