  Recent experiments on vanadium-based nonmagnetic kagom\'e metals
$A$V$_3$Sb$_5$ ($A=$ K, Rb, Cs) revealed evidence for possible spontaneous
time-reversal symmetry (TRS) breaking in the charge density wave (CDW) ordered
state. The long-sought-after quantum order of loop currents has been suggested
as a candidate for the TRS breaking state. However, a microscopic model for the
emergence of the loop-current CDW due to electronic correlations is still
lacking. Here, we calculate the susceptibility of the real and imaginary bond
orders on the kagom\'e lattice near van Hove filling, and reveal the importance
of next-nearest-neighbor Coulomb repulsion $V_2$ in triggering the instability
toward imaginary bond ordered CDW. The concrete effective single-orbital
$t$-$V_1$-$V_2$ model on the kagom\'e lattice is then studied, where $t$ and
$V_1$ are the hopping and Coulomb repulsion on the nearest-neighbor bonds. We
obtain the mean-field ground states, analyze their properties, and determine
the phase diagram in the plane spanned by $V_1$ and $V_2$ at van Hove filling.
The region dominated by $V_1$ is occupied by a $2a_0 \times 2a_0$ real CDW
insulator with the inverse of Star-of-David (ISD) bond configuration.
Increasing $V_2$ indeed drives a first-order transition from ISD to stabilized
loop-current insulators that exhibit four possible current patterns of
different topological properties, leading to orbital Chern insulators. We then
extend these results away from van Hove filling and show that electron doping
helps the stabilization of loop currents, and gives rise to doped orbital Chern
insulators with emergent Chern Fermi pockets carrying large Berry curvature and
orbital magnetic moment. Our findings provide a concrete model realization of
the loop-current Chern metal at the mean-field level for the TRS breaking
normal state of the kagom\'e superconductors.
