Flexible Li-CO Batteries with Boosted Reaction Kinetics and Cyclelife Enabled by Heterostructured MoN@TiN Cathode and Interface-protected Li Anode.

With theoretically endowing with high energy densities and environmentally friendly carbon neutralization ability, flexible fiber-shaped Li-CO battery emerges as a multipurpose platform for next-generation wearable electronics. Nevertheless, the ineluctable issues faced by cathode catalysts and Li anodes have brought enormous obstacles to the development of flexible fiber-shaped Li-CO batteries. Herein, a flexible fiber-shaped Li-CO battery based on MoN cathode coating with atomic layer deposited TiN and LiN protected Li anode is constructed. Owing to the regulation surface electrons of MoN by TiN, heterostructured cathode has more delocalized electrons which enable cathodes to stabilize 2-electron intermediate products LiCO by electron bridge bonds and avoid disproportionation into LiCO. LiN layers not only accelerate Li transportation but also avoid contact between Li and CO to form LiCO. Thus, the constructed Li-CO battery demonstrates a low charge potential of 3.22 V, low overpotential of 0.56 V, outstanding rate capabilities up to 1 A g, and excellent long-term cycling (≈2000 h) with an energy efficiency of ≈80%. The fabricated flexible fiber-shaped Li-CO battery shows an ultrahigh energy density of 14 772.5 Wh kg based on cathodes (340.8 Wh kg based on device mass), and outstanding deformations adaptability, giving it great potential for wearable electronics.