Dynamic spatial progression of isolated lithium during battery operations

Article

关键词: HIGH-ENERGY;    METAL BATTERIES;    LI-ION;    ELECTRODE;    ANODE;    HOST;   

DOI  :  10.1038/s41586-021-04168-w

来源: SCIE

【 摘 要 】

The increasing demand for next-generation energy storage systems necessitates the development of high-performance lithium batteries(1-3). Unfortunately, current Li anodes exhibit rapid capacity decay and a short cycle life(4-6), owing to the continuous generation of solid electrolyte interface(7,8) and isolated Li (i-Li)(9-11). The formation of i-Li during the nonuniform dissolution of Li dendrites(12) leads to a substantial capacity loss in lithium batteries under most testing conditions(13). Because i-Li loses electrical connection with the current collector, it has been considered electrochemically inactive or 'dead' in batteries(14,15). Contradicting this commonly accepted presumption, here we show that i-Li is highly responsive to battery operations, owing to its dynamic polarization to the electric field in the electrolyte. Simultaneous Li deposition and dissolution occurs on two ends of the i-Li, leading to its spatial progression toward the cathode (anode) during charge (discharge). Revealed by our simulation results, the progression rate of i-Li is mainly affected by its length, orientation and the applied current density. Moreover, we successfully demonstrate the recovery of i-Li in Cu-Li cells with >100% Coulombic efficiency and realize LiNi0.5Mn0.3Co0.2O2 (NMC)-Li full cells with extended cycle life.

【 授权许可】

Free