Na2.44Mn1.79(SO4)3: a new member of the alluaudite family of insertion compounds for sodium ion batteries

Putting alluaudite chemistry on the anvil, here we unveil Na_2+2xMn_2−x(SO₄)₃ as a potential 4.4 V Mn-based positive insertion material for sodium batteries. Assuming a three-dimensional monoclinic framework, it undergoes antiferromagnetic ordering at 3.4 K.