[en] Highlights: • An improved rule-based multiparameter battery cooling strategy is investigated. • The critical control parameters for the active battery thermal management system are proposed and validated. • The control strategy is evaluated regarding the battery-life loss and energy consumption. • The trade-off between battery life and vehicle drive range is studied. Most electric vehicles (EVs) utilize an active battery thermal management system (ABTMS) to improve the thermal safety of the lithium-ion battery and extend battery life. However, an ABTMS with an inappropriate control strategy cannot slow battery degradation and may even increase the energy consumption. This paper develops a comprehensive EV model with an air-cooling battery pack and proposes a rule-based multiparameter control strategy. On this basis, the effects of critical control parameters (target temperature, temperature fluctuation range, air flowrate, and refrigeration power) on EVs are studied and evaluated regarding the state of health (SoH) and ΔSoH of the battery and the ABTMS energy consumption. The following results were obtained after 2000 days of mixed driving cycles in a high-temperature environment. (1) When the target temperature is reduced by 6 K, the battery degradation rate decreases by 8.9%; however, the driving range decreases by 5.7%. (2) With an appropriate air flowrate, the battery degradation rate decreases by 2.4 ~ 4.4%, and the driving range increases by 2.1 ~ 5.5%. (3) The air flowrate more significantly affects the ABTMS than the refrigeration power. These findings help to better guide the parameter settings of this strategy to further slow battery degradation and extend the driving range.

[en] Herein we report an in-situ strategy for synthesizing NiO foamed sheet on Ni foam substrate which could achieve great improvement on the areal performance of battery-type supercapacitors. The anchored NiO foamed sheets are synthesized via a precursor growth step by hydrothermal oxidation, and followed by a pore-inducing step through heat treating. The physical characterizations indicate that this film product has a multi-level pore structure with high active surface area. As for electrode material, the anchored sheets could ensure excellent conductivity at the film/substrate interface, and the porous structure could form high free electron/ionic diffusion routes which facilitates the redox reactions for reversible energy storage. The electrochemical measurements show that the areal capacity of as-synthesized electrode could achieve 4.31–3.39 C cm⁻² at a wide current range of 10–200 mA cm⁻². The single supercapacitor device exhibits a high areal energy density of 9.84–9.45 W h m⁻² at a wide power density of 100–2000 W m⁻².

[en] Highlights: • The thermal performance of aligned, staggered, and cross battery packs is experimentally studied. • The effect of the discharge rate and air inlet temperature on the thermal management system is analyzed. • The energy efficiency of the air cooling battery thermal management system is investigated under various conditions. • The upper limitation for the cooling capacity is demonstrated in this paper. -- Abstract: To comprehensively investigate the characteristics of an air cooling system, a battery pack with 32 high energy density cylindrical lithium-ion batteries is designed in this paper. Using a series of evaluation parameters, the air cooling performances of aligned, staggered, and cross battery packs are experimentally studied and compared at different air inlet velocities. Additionally, the cooling effect and capacity of the air cooling system are investigated by changing the discharge rate and air inlet temperature. Finally, the energy efficiency of the air cooling system under various operating conditions is studied. It is found that the aligned arrangement has the best cooling performance and temperature uniformity, followed by the staggered and finally the cross arrangement. The minimum temperature always occurs in the second column along the direction of the air inlet. The parasitic power consumption increases exponentially with the air inlet velocity, and the aligned arrangement has the lowest power consumption, up to 23% less than that of the cross arrangement. Additionally, the energy efficiency of the air cooling system decreases with the increasing air velocity, and the cooling capacity has an upper limit that is proportional to the discharge rate.

[en] Cupric ion substituted LiFePO_4/C composites were successfully synthesized via a two-step solid state reaction method. The SEM mapping demonstrates that cupric is well substituted in LiFePO_4. Interestingly, the XRD spectra indicate that the substituted cupric could enlarge the interplanar distance of planes that parallelled to [010] direction of LiFePO_4 crystallines, which could widens the diffusion channels of Li"+ along [010] direction. For further research, Lithium ion storage behavior of as-synthesized cupric ion substituted LiFePO_4/C products were investigated via various electrochemical strategies, and the highest capacity of 152.4, 144.4, 126.7 and 110.5 mAh g"−"1 was achieved by LiFe_0_._9_8_5Cu_0_._0_1_5PO_4/C at discharge rate of 1, 2, 5, and 10 C, respectively. Compared the result with that of LiFePO_4/C, we can see that cupric ion substituted LiFePO_4/C composites show enhanced electrochemical activity for Li"+ storage with decreased overpotential and increased high rate capability for electrochemical reaction

[en] A novel lanthanum phosphate and carbon co-coated LiFePO_4 cathode material successfully prepared via liquid-phase precipitation reaction combined with carbothermal reduction method has been studied in Li"+ ion batteries. The LiFePO_4 electrode modified by carbon layer deposited with appropriate amount of lanthanum phosphate shows higher reversible capacity and stable cycle performance compared with the LiFePO_4/C electrode. These superior performances are owing to the good conductivity and stability of the hybrid coating layer which enhances the electron and Li"+ ion transport on the surface of the LiFePO_4 material, thus elevates the transfer kinetics of the electrode. The LiFePO_4/C-LaPO_4 (4.0 mol%) electrode showed a stable cyclability and the highest capacity among all the LiFePO_4/C-xLaPO_4 samples. The initial discharge capacity of the LiFePO_4/C-LaPO_4 (4.0 mol%) electrode was 150.7, 142.3, 116.6 and 80.3 mA h g"−"1 at 1, 2, 5 and 10 C rates, respectively