The wikipedia claims that there is a model category structure of the category of arbitrary chain-complexes of R-modules which is defined by:
weak equivalences are chain homotopy equivalences of chain-complexes;
cofibrations are monomorphisms that are split as morphisms of underlying R-modules; and
fibrations are epimorphisms that are split as morphisms of underlying R-modules.
But I have no idea on how to prove the lifting property and the factorization. More precisely, how should I verify the axioms:
MC4 Given maps f,g,i,p such that pf=gi, a lift h (i.e. ph=g, f=hi) exists in either of the following two situations: (i) i is a cofibration and p is an acyclic fibration, or (ii) i is an acyclic cofibration and p is a fibration.
and
MC5 Any map f can be factored in two ways: (i) f = pi, where i is a cofibration and p is an acyclic fibration, and (ii) f = pi, where i is an acyclic cofibration and p is a fibration?