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An all-lead redox flow battery in a fluoroboric acid electrolyte is proposed.The same electrolyte was used as both the negative and positive electrodes,and it consists of a high concentration solution of Pb(BF_4)_2 in aqueous fluoroboric acid,i.e.,0.1,0.5,1.0 and 1.5 mol·L~(-1) Pb(BF_4)_2 in 1.0 mol·L~(-1) HBF_4.The properties of the graphite and glassy carbon electrodes for both the positive and negative electrodes as current collectors were compared using cyclic voltammetry.We found that the graphite substrate was better than glassy carbon for both the negative electrode and the positive electrode.The all-lead redox flow battery was constructed using graphite substrates as both the positive and negative electrodes with a single electrolyte flow passing though the two electrodes.The performance of the batteries was evaluated using the constant current charge/discharge technique.Typically,an average coulombic efficiency of above 87%and an average energy efficiency of above 68%were obtained.An average energy efficiency of above 74%was achieved with electrolyte containing 1.0 or 1.5 mol·L~(-1) Pb(BF_4)_2 + 1.0 mol·L~(-1) HBF_4 at current densities of 10 and 20 mA·cm~(-2).

MoOx doped 4,4,4-tris(N-(3-methylphenyl)-N-phenylamin) triphenylamine (m-MTDATA) is used as a hole transport layer to improve the efficiency of CuPc/C60 small molecular organic photovoltaics. A series of devices is fabricated in a high vacuum system. One of the devices with the structure of indum tin oxides (ITO)/m-MTDATA:MoOx(3:1)(30 nm)/CuPc(20 nm)/C60(40 nm)/Bphen (8 nm)/LiF(0.8 nm)/Al(100 nm) shows that the following parameters are achieved: the open circuit voltage Voc = 0.40 V, short-circuit current Jsc=6.59 mA/cm2, fill factor of 0.55, and power conversion efficiency p=1.46% under AM1.5 solar illumination. The efficiency of the device is improved by 38% compared with that of the device without hole transport layer ITO/CuPc(20 nm)/C60(40 nm)/Bphen(8 nm)/LiF(0.8 nm)/Al(100 nm). The improvement of the device performance may be attributed to the addition of m-MTDATA:MoOx (3:1) (30 nm) hole transport layer that reduces the contact resistance between the ITO electrode and the organic layer, thus reducing the overall device series resistance and improving the efficiency of the device.