Reallocation of active lithium by regulating electrochemical structural connectivity in anode‐free lithium metal batteries

Anode‐free Li metal batteries (AFLMBs) impose stringent demands on active Li utilization due to the absence of exogenous Li. Moreover, the poor cycling reversibility of Li metal and significant active Li loss have hindered the development of AFLMBs. Herein, for the first time, we establish the correlation between the electrochemical structural connectivity of Li deposits and the loss pathways of active Li. Li nucleation behavior is optimized via the self‐driven formation of hydroxyl‐modified lithiophilic Cu nanoparticles from CuOHF. Dense columnar Li stacks with stable bulk‐phase electronic pathways and interfacial kinetic structures are achieved through a high‐density spatial multidimensional nucleation mechanism, which restricts the quasi‐linear accumulation of irreversible Li to only 0.003 mg per cycle. Meanwhile, the regulated Li growth process exhibits homogeneous and rapid interfacial mass transfer with extremely low concentration polarization. The anode‐free LiFePO 4 pouch cell retains 61.4% of its initial reversible capacity after 100 cycles. Insights into active Li utilization derived from this work will accelerate the development of high‐performance AFLMBs.