We present time-dependent Born effective charges of B and O in lithium borate melts determined by ab initio molecular dynamics (AIMD) simulations. The Born charge, based on polarization theory, is calculated from all atoms at each time step of the AIMD run. The time-averaged charge distributions are obtained for specific chemical species such as three-coordinated B, four-coordinated B, bridging O (O-b) and, non-bridging O (O-nb). O-b and O-nb have similar time-averaged charge distributions, indicating that positively charged Li+ is compensated not only by O-nb but also by the glass network of the melt as a whole. (C) 2014 Elsevier B.V. All rights reserved.