Construction Of Ultra-high Mass Loading 3D Porous Electrodes Based On New Binder

With the proliferation of portable electronic products and electric vehicles,it is essential to increase the energy density of batteries.The research and development of electrode materials have achieved a higher energy density.However,it is generally only possible to achieve good performance in ultra-thin electrodes with low mass loading,and it is difficult to achieve good performance in thick electrodes with high mass loading.A new electrode structure needs to be designed to achieve excellent performance under ultra-high mass loading.As an electrode component,the binder plays a vital role in improving electrochemical performance.As a result,a new type of binder was prepared based on natural gum,combined with freeze-drying method to synthesize the ultra-high mass loading electrodes,and the properties of the binder and electrode materials were discussed.The main findings are as follows:The feasibility of xanthan gum binder used in high mass loading thick electrodes was explored.Xanthan gum was compounded with locust bean gum to synthesize a binder with higher viscosity than xanthan gum.This new type of binder was used in the manufacture of Li Ni0.8Co0.1Mn0.1O2（NCM811）thick electrodes,and a three-dimensional porous electrode with a low tortuosity structure was successfully prepared.The ultra-high area capacity of 79.3 m Ah cm^-2 was achieved when the active material mass loading up to 511 mg cm^-2.The method can be extended to other electrode materials,such as Li Fe PO4（LFP）and Li4Ti5O12（LTO）.Xanthan gum and guar gum were compounded for thick electrodes manufacturing.The results show that the performance of the binder is obviously better than that of the traditional PVDF binder.It can support up to 99.5%of the active substance,greatly reducing the proportion of inactive components and saving costs.When the active material mass loading up to 538 mg cm^-2,the area capacity is as high as 93.4 m Ah cm^-2,which is about 30 times that of conventional electrodes(about 3 m Ah·cm^-2),which is the highest value reported so far.