Wave-like Cu substrate with gradient {100} texture for anode-free lithium batteries

Abstract

Anode-free lithium batteries (AFLBs) directly utilize current collectors (CCs) as the lithium-deposition substrates to achieve maximum energy density and minimum lithium redundancy. However, without Li compensation from the anode, the loss of active lithium is sharply intensified due to the generation of dead lithium and the side reactions between the electrolyte and electrode, resulting in a rapid decline in capacity and poor cycling stability. Herein, a wave-like Cu substrate with highly (100)-preferential orientation (wCu(100)-H) is proposed as the sustainable CC for AFLBs, which displays a gradient {100} texture component from valleys (96.8 %) to peaks (47.1 %). Specifically, the periodic micro-valley structure with an enlarged surface area suppresses Li dendrite growth by reducing the local current density. Moreover, the gradient distribution of the Cu(100) facet achieves a spatially oriented Li deposition pattern. As a result, the anode-free LiFePO₄-based and LiNi_0.8Co_0.1Mn_0.1O₂-based full cells exhibit remarkable capacity retentions of 87 % (120 cycles) and 77 % (110 cycles), respectively. The successful construction of the wCu(100)-H provides a fresh insight into the exquisite modification of CC and a significant step toward realizing high-performance AFLBs.