锂电池性能的分析研究

通过建立函数关系,研究了电池寿命与电池内阻、电池组内均衡性、电池的充电电流、充电电压的关系,指出蓄电池组的寿命与上述的任何一个量的关系都不是独立的,都与其他物理量有着联系,对于延长电池的寿命、改善电池性能有一定的意义。

Chip Design of Li-Ion Battery Charger Operating in Constant-Current/Constant-Voltage Modes

A design for a Li-ion battery charger IC that can operate in a constant current-constant voltage （CC- CV） charge mode is proposed. In the CC-CV charge mode,the charger IC provides a constant charging current at the beginning, and then the charging current begins to decrease before the battery voltage reaches its final value. After the battery voltage reaches its final value and remains constant,the charging current is further reduced. This approach prevents charging the battery with full current near its saturated voltage,which can cause heating. The novel design of the core of the charger IC realizes the proposed CC-CV charge mode. The chip was implemented in a CSMC 0.6μm CMOS mixed signal process. The experimental results verify the realization of the proposed CC- CV charge mode. The voltage of the battery after charging is 4. 1833V.

创新山地自行车的研究

目的:实现自行车在爬坡过程中电动机提供助力,下坡过程中电动机作发电机用给蓄电池充电。方法:将电动机与自行车后轮轴链条连接,发出的电经过整流器,变压器后再充入蓄电池。结果:电动机能够带动自行车爬坡并且充电效率可以达到32%左右。结论:这款创新自行车能够实现自主的放电和充电功能。

Proposal and Analyses of Resonant Bilateral Converter Employing Simple Zero Current Switches

With the development of devices for high performance, the circuit technologies have been also studied. One of the main streams concerns a soft switching technology to mitigate switching stress, leading to the reduction in switching losses or electro-magnetic noise. On the other hand, as a characterized orthodox technology＇, the existing chopper circuit is used for the electric vehicles, etc.. Such technologies have a tendency to go out of vogue as power supplies for such vehicles. However, as a boost chopper for the battery charger for an electric vehicle, those technologies become a main stream, where a bilateral function is required. With the foregoing in mind, the authors have devised and analyzed the bilateral chopper using the soft-switch technology, which could be applied to a battery charger for an electric vehicle or similar.

Effect of Temperature on the Organic Solar Cells Parameters

The dependence of the organic solar cells parameters, e.g., the shirt circuit current Isc, open circuit voltage Vo,., the fill factor FF and the efficiency eta on temperature is investigated. By expressing the different equations which link the parameters with temperature, it is observed that the short circuit current Isc increases so monotonous with temperature and then saturates to a maximum value before decreasing at high temperatures. The open circuit voltage V∝ decreases linearly with the increasing of the temperature. The fill factor FF and the efficiency eta which are directly related with short circuit current Isc and the open circuit voltage V∝ follow their variations.

Alloy-like ternary polymer solar cells with over 17.2% efficiency

Ternary strategy has been considered as an efficient method to achieve high performance polymer solar cells(PSCs). A power conversion efficiency(PCE) of 17.22% is achieved in the optimized ternary PSCs with10 wt% MF1 in acceptors. The over 8% PCE improvement by employing ternary strategy is attributed to the simultaneously increased JSCof 25.68 mA cm^-2, VOCof 0.853 V and FF of 78.61% compared with Y6 based binary PSCs. The good compatibility of MF1 and Y6 can be confirmed from Raman mapping, contact angle,cyclic voltammetry and morphology, which is the prerequisite to form alloy-like state. Electron mobility in ternary active layers strongly depends on MF1 content in acceptors due to the different lowest unoccupied molecular orbital(LUMO) levels of Y6 and MF1, which can well explain the wave-like varied FF of ternary PSCs. The third-party certified PCE of 16.8% should be one of the highest values for single bulk heterojunction PSCs. This work provides sufficient references for selecting materials to achieve efficient ternary PSCs.

Cubic imidazolate frameworks-derived CoFe alloy nanoparticles-embedded N-doped graphitic carbon for discharging reaction of Zn-air battery

The construction of transition metal-based catalysts with high activity and stability has been widely regarded as a promising method to replace the precious metal Pt for oxygen reduction reaction(ORR).Herein,we synthesized CoFe alloy nanoparticle-embedded N-doped graphitic carbon(CoFe/NC)nanostructures as ORR electrocatalysts.The ZIF-67(zeolitic imidazolate framework,ZIF)nanocubes were first synthesized,followed by an introduction of Fe2+ions to form CoFe-ZIF precursors via a simple ion-exchange route.Subsequently,the CoFe/NC composites were synthesized through a facile pyrolysis strategy.The ORR activity and the contents of cobalt and iron could be effectively adjusted by controlling the solution concentration of Fe2+ions used for the ion exchange and the pyrolysis temperature.The CoFe/NC-0.2-900 composite(synthesized with 0.2 mmol of FeSO4·7H2O at a pyrolysis temperature of 900℃)exhibited ORR activity that was superior to the other samples owing to a synergistic effect of the bimetal,especially considering the extremely high limiting current density of 6.4 mA cm^-2 compared with that of Pt/C(5.1 mA cm^-2).Rechargeable Zn-air batteries were assembled employing CoFe/NC-0.2-900 and NiFeP/NF(NiFeP supported on nickel foam(NF))as the catalysts for the discharging and charging processes,respectively,The above materials achieved reduced discharging and charging platforms,high power density,and prolonged cycling stability compared with conventional Pt/C+RuO2/C catalysts.

Bilayer broadband antireflective coating to achieve planar heterojunction perovskite solar cells with23.9%efficiency

Although perovskite solar cells(PSCs)have achieved encouraging efficiency,the photon loss at the substrate due to light reflection has not been well addressed.Light management is promising to reduce reflection loss and realize higher power conversion efficiency(PCE)of PSCs.Here,a bilayer antireflective coating(ARC)has been designed and coated onto the backside of the glass substrate of(FAPbI_(3))_(x)(MAPbBr_(3))_(1-x)PSCs to enhance photon harvesting and consequently the device efficiency.The bottom layer of the bilayer ARC is made from a silica polymer and the top layer is made from the mixture of hexamethyldisiloxane-modified mesoporous silica nanoparticles and a fluorinated silica polymer.By adjusting the refractive index and the film thickness of each layer according to a two-layer model,enhanced glass transmittance in a broadband wavelength range can be reached,with the maximum transmittance increasing from ca.90%to over 95%.With the bilayer ARC,the maximum short-circuit current density and PCE of(FAPbI_(3))_(x)(MAPbBr_(3))_(1-x)PSCs can be increased from 25.5 m A cm^(-2)and 22.7%to 26.5 mA cm^(-2)and 23.9%with negligible changes in fill factor and opencircuit voltage.This work presents a simple yet effective strategy to enhance the efficiency of solar cells employing bilayer antirefective coatings,which can be applied to other types of solar cells.