A long range disordered alpha-MnO2 phase has been synthesized from the reduction of an aqueous K+ permanganate solution by fumaric acid in acidic medium. Its formula is K0.062MnO2 . 0.43H(2)O. From XRD measurements on heat-treated samples, it has been assumed a hollandite-type structure for this new phase. The high oxidation state of Mn and the low content of K+ ions within the channels of the structure raise the possibility of utilizing this alpha-MnO2 framework as a rechargeable cathodic material for secondary lithium batteries. With a theoretical faradaic yield of 0.9 F.mol(-1) leading to a specific capacity of 280 Ah.kg(-1) available between 4.1 and 2.3 V, this material exhibits the best performances of alpha-MnO2 forms. Lithium insertion occurs in one single electrochemical step and the presence of structural water is shown to ensure the rechargeability of the insertion process. During galvanostatic cycling at C/20, in the potential range 4.1 V-2.3 V, with an initial d.o.d of Delta x = 0.6, the specific capacity rapidly decreases to 120 Ah.kg(-1) after which it stabilizes for at least 20 cycles. Cycling experiments can be performed by involving higher d.o.d but without obtaining similar results.