Carbonyl-Based π-Conjugated Materials: From Synthesis to Applications in Lithium-Ion Batteries.

The constant growth in the global energy demand together with the increasing awareness of clean and sustainable development has strongly pushed scientists to search for metal-free, low-cost, environmentally friendly functional energy-storage systems (ESSs). Among the reported organic electrode materials, carbonyl-based π-conjugated compounds show excellent rate capabilities and cycling stabilities and are powerful candidates for the next generation of rechargeable lithium-ion batteries (LIBs). Benefiting from the molecular structure versatility and design feasibility, the electrochemical properties of organic and polymeric materials can be easily tuned. This Review summarizes recent efforts in the search for carbonyl-based π-conjugated electrode materials in LIBs with a focus on the synthetic strategies developed to improve their electrochemical performance. The use of these materials in flexible, all-organic LIBs is highlighted as a unique direction towards widespread applications of LIBs.