Preparation Of Wood-derived Carbon Current Collectors And Their Application In Zinc-based Batteries

Increasing energy and environmental problems have contributed to the search for efficient energy storage devices.Among the many energy storage devices,aqueous zinc-based batteries have received much attention for their high safety,low cost,high theoretical capacity and low redox potential.The current collector is an indispensable component to connect the zinc-based battery to the external circuit and has a great impact on the capacity,multiplication performance and cycling stability of the zinc-based battery.Wood-derived carbon（WDC）current collectors are well suited for efficient energy storage due to their hierarchical porous structure,photothermal responsiveness and abundance of active sites.Herein,the versatility of WDCs was utilized to prepare three separate cathode materials for application in zinc-based batteries,as follows.（1）A WDC electrode with single-sided growth of cobalt-nickel sulfide and hydroxide（CNSOH@WDC）was prepared by an electrodeposition process.Due to the intrinsic channel structure of WDC and the asymmetric wettability caused by the single-sided growth of the hydrophilic active material CNSOH,the electrode material possesses a unique three-phase interfacial channel and exhibits the combined function of a current collector and a gas diffusion layer.The quasi-solid hybrid zinc cell with CNSOH@WDC as the anode can simultaneously perform both Zn-air and Ni-Zn cell reactions and exhibits a high specific capacity of 656.5 m Ah g^-1 at a current density of 1 m A cm^-2,in addition to an excellent energy density(644.7 Wh kg^-1)and good cycling stability.（2）A WDC/Mn O₂ hybrid electrode（Mn O₂@WDC）was prepared by an electrodeposition process.The electrode takes advantage of the excellent photothermal response of WDC and can enhance its energy storage capacity by rapidly increasing the surface temperature by irradiating only sunlight.（The surface temperature increases by 53.3 ^oC within 30 min,and the area specific capacity increases to 183.5%of the original）.Under illumination,the quasi-solid-state zinc ion battery with Mn O₂@WDC as the anode exhibits a high specific capacity of 1.16 m Ah cm^-2 at a current density of 0.5 m A cm^-2.（3）A WDC/1,5-naphthalenediamine hybrid electrode（P（1,5-NAPD）@WDC）was prepared by an electropolymerization process.The electrode was loaded with a higher quality of P（1,5-NAPD）using the abundant active sites of the WDC collector,and the higher entropy value and entropy change of P（1,5-NAPD）resulted in a strong low temperature performance of the electrode material.The quasi-solid-state zinc ion battery with P（1,5-NAPD）@WDC as the positive electrode in a low-temperature environment（-30 ^oC）exhibited a specific capacity of 0.43 m Ah cm^-2 and excellent low-temperature stability at a current density of 2 m A cm^-2.