Summary: ``A collisional particle code based on implicit energy- and charge-conserving methods is presented. A modified version of the {\it particle-suppressed} Jacobian-Free Newton-Krylov method that can enhance the solver efficiency is introduced. Mathematically, it is shown that this new approach can be viewed as a fixed-point iteration method for the particle positions. The model can {\it exactly} conserve global energy and local charge and can efficiently use time steps larger than the plasma period. The algorithm's ability to simulate dense plasmas accurately and efficiently is quantified by simulating the dynamic compression of a plasma slab via a magnetic piston in 1D planar geometry.''