Quasi-compensatory effect in emerging anode-free lithium batteries

As electric vehicle (EV) sales grew approximately 50% year-over-year, surpassing 3.2 million units in 2020, the “roaring era” of EV is around the corner. To meet the increasing demand for low cost and high energy density batteries, anode-free configuration, with no heavy and voluminous host material on the current collector, has been proposed and further investigated. Nevertheless, it always suffers from several nonnegligible “bottlenecks”, such as fragile solid electrolyte interface, deteriorated cycling reversibility, and uncontrolled dendrite formation. Inspired by the “compensatory effect” of some disabled people with other specific functions strengthened to make up for their inconvenience, corresponding quasi-compensatory measures after anode removal, involving dimensional compensation, SEI robustness compensation, lithiophilicity compensation, and lithium source compensation, have been carried out and achieved significant battery performance enhancement. In this review, the chemistry, challenges, and rationally designed “quasi-compensatory effect” associated with anode-free lithium-ion battery are systematically discussed with several possible R&D directions that may aid, direct, or facilitate future research on lithium storage in anode-free configuration essentially emphasized.