Design lithium modified multifunctional additive for ultra-high loading electrode toward solvent-free lithium-ion battery

High energy density batteries rely on electrodes with high mass loading, which inevitably leads to increased electrode thickness. However, increasing electrode thickness introduces several drawbacks, including reduced electrolyte penetration and prolonged ion diffusion paths, which significantly compromise the electrochemical stability of electrodes. In this study, lithium carboxymethyl cellulose (CMC-Li) is synthesized via an ion-exchange method and incorporated into high mass loading electrodes to optimize the structure of the electrodes and enhance electrochemical performance. The incorporation of CMC-Li provides multiple significant advantages: (i) CMC-Li increases the number of large pores of electrode and reduces electrode tortuosity, improving electrolyte infiltration and facilitating Li⁺ diffusion kinetics of electrode. (ii) The abundant ether‑oxygen groups and coordinated lithium in CMC-Li promote Li⁺ conduction. (iii) CMC-Li facilitates the formation of a more stable SEI. Benefit from multiple advantages, the DF/CMC-Li electrode with a mass load of 8.5 mg cm⁻² demonstrating a capacity retention of 71.05 % after 300 cycles at 1C. Moreover, an ultra-high mass loading anode of 78.7 mg cm⁻² demonstrating an areal capacity of 6.71 mAh cm⁻². The incorporation of CMC-Li optimizes the porous architecture of anodes, demonstrating its potential for enabling the fabrication of dry-processed electrodes with high energy density and stable electrochemical performance.