The limitations in potential for the electroactive material of the negative electrode are less important than in the past thanks to the advent of 5 V electrode materials for the cathode in lithium-cell batteries. However, to maintain cell voltage, a deep study of new electrolyte–solvent combinations is required.
Lithium (Li) metal is widely recognized as a highly promising negative electrode material for next-generation high-energy-density rechargeable batteries due to its exceptional specific capacity (3860 mAh g −1), low electrochemical potential (−3.04 V vs. standard hydrogen electrode), and low density (0.534 g cm −3).
Carbon materials, including graphite, hard carbon, soft carbon, graphene, and carbon nanotubes, are widely used as high-performance negative electrodes for sodium-ion and potassium-ion batteries (SIBs and PIBs).
Lithium (Li) metal shows promise as a negative electrode for high-energy-density batteries, but challenges like dendritic Li deposits and low Coulombic efficiency hinder its widespread large-scale adoption.
The electrochemical reaction at the negative electrode in Li-ion batteries is represented by x Li + +6 C +x e − → Li x C 6 The Li + -ions in the electrolyte enter between the layer planes of graphite during charge (intercalation). The distance between the graphite layer planes expands by about 10% to accommodate the Li + -ions.
As the negative electrode material of SIBs, the material has a long period of stability and a specific capacity of 673 mAh g −1 when the current density is 100 mAh g −1.