The Study On The Nano Carbon Composites Of Beta-FeOOH As The Catalyst Of The Air Electrode Of The Lithium Air Battery

With the development of science and technology, people put forward higher requirements for mobile power, especially for improving the capacity of the battery.. Because of its close to gasoline energy, and the actual capacity of the lithium air battery, the air battery of the lithium air battery has got the attention of the people. At present, lithium air battery catalyst with good performance mostly for precious metals, expensive cost. So to find a cheap and activity catalyst materials can greatly promote the development of lithium air battery. The transition metal(hydr) oxides have great potential. In this paper, aiming at finding transition metal(hydr) oxides as catalyst materials for lithium air batteries, β-Fe OOH nanorods were synthesized, and were composited with graphene and CMK to improve the conductivity, specific surface area and porosity. And the performance of β-Fe OOH nanorods and its carbon composite materials in the lithium air battery were studied.β-Fe OOH nanorods are prepared by a one-step hydrothermal method. Through the analysis of the temperature, reactant concentration, heating time and solvent composition factors effect on the product synthesis and eventually the synthesis conditions optimization, the hydrothermal reaction is performed in 80 ℃, reaction time was 4h, 0.1M Fe Cl3, were successfully fabricated by high purity, 500 nm length and 100 nm diameter of β-Fe OOH nanorods. Then the β-Fe OOH/r GO and β-Fe OOH/CMK composites were also prepared by the appropriate changes of the conditions.The β-Fe OOH nanorods, β-Fe OOH/r GO and β-Fe OOH/CMK composites as catalysts, mixing with Super P(conductive additive), were prepared gas diffusion electrode of lithium-air batteries. Charge-discharge cycle tests showed that β-Fe OOH nanorods have good catalytic activity in lithium-air batteries, the electrode active material and the Super P ratio of 6:2, the specific capacity of 4918 m Ah g-1(carbon), while at a current density of 200 m A g-1(carbon), specific capacity limit 600 m Ah g(carbon)-1, cycling for 76 times. But when the current density reaches 500 m A g-1(carbon), after 5 cycles, the battery internal polarization became serious. Using β-Fe OOH/r GO as a catalyst, since the specific surface area and conductivity greatly improved material, which reached a 10400 m Ah g-1(carbon), at a current density of 500 m A g-1(carbon), limiting capacity was 600 m Ah g-1(carbon), the tolerance of 60 cycles; β-Fe OOH/CMK due to the excellent conductivity and rich porosity of CMK, the specific capacity has been greatly improved, reaching at 9000 m Ah g(carbon)-1,and excellent cycle performance, at current density of 500 m A g-1, limits capacity was 600 m Ah g(carbon)-1, withstood 90 cycles.