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LiMn_2O_4 nanoparticles are facilely synthesized using a sol—gel processing method.Graphene is added to LiMn_2O_4 electrode aiming at increasing specific capacity and improving rate capability.In order to further improve cycling stability of LiMn_2O_4/graphene electrode,atomic layer deposition(ALD)is used to deposit ultrathin ZnO coating composed of six ZnO ALD layers and modify the surface of either LiMn_2O_4/graphene electrode or individual LiMn_2O_4 particles to form nanoarchitectured LiMn_2O_4/graphene/ZnO electrodes.Both ZnO-ALD-modified LiMn_2O_4/graphene electrodes demonstrate enhanced cycling performance at 1C retaining the final discharge capacity above 122 mA h g~(-1)after 100 electrochemical cycles,which is higher than115 mA h g~(-1)of pristine LiMn_2O_4/graphene electrode and 109 mA h g~(-1)of bare LiMn_2O_4 electrode.The improved electrochemical performance of nanoarchitectured LiMn_2O_4/graphene/ZnO electrodes can be attributed to the cooperative effects from high electronic conductivity of graphene sheets to facilitate electron transportation and effective protection of ZnO ALD coating to restrict Mn dissolution and electrolyte decomposition.
LiMn 2 O 4 nanoparticles are facilely synthesized using a sol-gel processing method. Graphene is added to LiMn 2 O 4 electrode aiming at increasing specific capacity and improving rate capability. In order to further improve cycling stability of LiMn 2 O 4 / graphene electrode, atomic layer deposition (ALD) is used to deposit ultrathin ZnO coating composed of six ZnO ALD layers and modify the surface of either LiMn_2O_4 / graphene electrode or individual LiMn_2O_4 particles to form nanoarchitectured LiMn_2O_4 / graphene / ZnO electrodes.Both ZnO-ALD-modified LiMn_2O_4 / graphene electrodes demonstrate enhanced cycling performance at 1C retaining the final discharge capacity above 122 mA hg -1 after 100 electrochemical cycles, which is higher than 115 mA hg -1 of pristine LiMn 2 O 4 / graphene electrode and 109 mA hg -1 of bare LiMn 2 O 4 electrode . The improved electrochemical performance of nanoarchitectured LiMn 2 O 4 / graphene / ZnO electrodes can be attributed to the cooperative effects from high elect ronic conductivity of graphene sheets to facilitate electron transportation and effective protection of ZnO ALD coating to restrict Mn dissolution and electrolyte decomposition.