Is there any good reference for the Pontrjagin ring structure on $$ H_\ast(K(\mathbb{Z}/2,k);\mathbb{Z}/2)\cong H_\ast(\Omega K(\mathbb{Z}/2,k+1);\mathbb{Z}/2)? $$ I am familiar with Serre's theorem describing the mod 2 cohomology ring structure. I'm also aware that the action of the DyerLashof operations on this infinite loop space is trivial.

By naturality and the external Cartan formula, the standard polynomial generators of $H^*(K(\mathbf{Z}/2,k);\mathbf{Z}/2)$ given by iterated Steenrod operations on the fundamental class are primitive. Therefore the homology is a divided power algebra on the dual elements. 

