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The transportation sector is under increasing pressure to reduce greenhouse gas emissions by decarbonizing its operations. One prominent solution that has emerged is the adoption of electric vehicles (EVs). As the electric vehicles market experiences rapid growth, the utilization of lithium-ion batteries (LiB) has become the predominant choice for energy storage. However, it is important to note that lithium-ion battery technology is sensitive to factors, like excessive voltage and temperature. Therefore, the development of an accurate battery model and a reliable state of charge (SOC) estimator is crucial to safeguard against the overcharging and over-discharging of the battery. Numerous studies have been conducted to address lithium-ion battery cell modeling and SOC estimations. These studies have explored variations in the number of RC networks within the model and different estimation methods. However, it is worth mentioning that the capacity of a single lithium-ion battery cell is relatively low and cannot be directly employed in electric vehicles. To meet the total capacity and voltage requirements for electric vehicles, multiple cells are typically connected in series or parallel configurations to form a battery pack. Surprisingly, this aspect has often been overlooked in previous research. To tackle this overlooked challenge, our study introduces a comprehensive battery pack model and an advanced Battery Management System (BMS). We then integrate these components into an electric vehicle model. Subsequently, we simulate the integrated EV-BMS model under the conditions of four different urban driving scenarios to replicate real-world driving conditions. The BMS that we have developed includes an Extended Kalman Filter (EKF)-based SOC estimation system, a mechanism for controlling coolant flow, and a passive cell-balancing algorithm. These components work together to ensure the safe and efficient operation of the battery pack within the electric vehicles. [ABSTRACT FROM AUTHOR]

Huge volume variation plagued silicon for large-scale application in high energy density lithium ion batteries serving as anodic materials, making active layers cracked or delaminated from current collectors after several cycles. To address this issue, a free-standing 3D porous carbon based current collector with recoverable mechanical robustness is dedicatedly designed and fabricated. Atmospheric pressure Ar plasma jet irradiation is applied to transit its surface wettability from hydrophobic to hydrophilic, making it compatible with the aqueous slurry casting process. Embedding Si nanoparticles without any architecture modification into such a state-of-the-art current collector delivers an excellent reversible capacity (1138 mAh g −1 ), prolonged cycling performance (>400 cycles) at the current density of 0.5 A g −1 and low capacity fading rate (<0.09% per cycle). This also provides considerable opportunities as a current collector of choice for the energy storage units in the ever-growing flexible and wearable electronic devices. [ABSTRACT FROM AUTHOR]

Li 4 Ti 5 O 12 /hierarchical porous carbon matrixes composites are successfully prepared by a facile and fast polymers assisted sol–gel method, aiming to promote both electronic and ionic conductivity. As indicated by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis, three less expensive cost and available water soluble polymers (e.g. PAA, CMC, and SA) can homogeneously react with Li–Ti–O precursor to incorporate into interior of nano-scale lithium titanate and provide a continues conductive network after pyrolysis. In addition, the results of scanning electron microscopy and transmission electron microscopy also prove that the Li 4 Ti 5 O 12 nanoparticles are firmly embedded in porous carbon matrix with no obvious agglomeration. EIS measurement and cyclic voltammetry further reveal that the facilitated electrode kinetics and better ionic transport of Li 4 Ti 5 O 12 /hierarchical porous carbon matrixes composites than that of Li 4 Ti 5 O 12 . The c-CMC-LTO exhibits a superior capacity of 92 mAh g −1 and retains its initial value with no obviously capacity decay over 200 cycles under an ultra-high C rate (50 C). [ABSTRACT FROM AUTHOR]

Silicon (Si) has been perceived as a promising next-generation anode material for lithium ion batteries (LIBs) due to its superior theoretical capacity. Despite the natural abundance of this element on Earth, large-scale production of high-purity Si nanomaterials in a green and energy-efficient way is yet to become an industrial reality. Spray-drying methods have been exploited to recover Si particles from low-value sludge produced in the photovoltaic industry, providing a massive and cost-effective Si resource for fabricating anode materials. To address such drawbacks like volume expansion, low electrical and Li + conductivity and unstable solid electrolyte interphase (SEI) formation, the recycled silicon particles have been downsized into nanoscale and shielded by a highly conductive and protective graphene multilayer through high energy ball milling. Cyclic voltammetry and electrochemical impedance spectroscopy measurements have revealed that the graphene wrapping and size reduction approach have significantly improved the electrochemical performance. It delivers an excellent reversible capacity of 1,138 mA h g −1 and a long cycle life with 73% capacity retention over 150 cycles at a high current of 450 mA g −1 . The plentiful waste conversion methodology also provides considerable opportunities for developing additional rechargeable devices, ceramic, powder metallurgy and silane/siloxane products. [ABSTRACT FROM AUTHOR]

• Ni-rich cathode materials for lithium ion battery. • Synthesis mechanism establishment for NMC811. • Tuning (003) spacing via boron-ion doping enhancing performance. • Ex-situ XRD for phase transformation during charging–discharging process. High nickel layered oxides (LiNi 0.8 Co 0.1 Mn 0.1 O 2, NMC811) demonstrate high capacity (≥ 200 mA h/g) and low cost, making them increasingly attractive as a high energy active cathode to replace LiCoO 2 or LiFePO 4 for lithium ion batteries. Nevertheless, their large scale practical applications are still inhibited by the low structural stability, insufficient rate capability and cyclability. In this work, a stable and safe LiNi0.8Co0.1Mn0.1O2 cathode was synthesized by facile oxalic acid assisted co-precipitation method. Boric acid has been chosen and utilized as a co-sintering agent to enhance the electrochemical performance via fine tuning internal interplanar space between transition metal oxide (003) layers. The B03 sample with 3.0 at% of boron doping exhibited a sustainable reversible capacity as high as 220 mA h g−1 with approximate 97% capacity retention after 100 cycles at 0.5 C charging/discharging rate. It also delivered 93 mA h/g under 10 C rate testing. In the long-term cycling test, this B03-NMC 811 cathode demonstrated 83% capacity retention after 300 cycles at 5 C cycling test. Appropriate adding of boron not only enhanced their C-rate capability and cyclability but also improved their structural stability during repetitive charging and discharging process through ex situ XRD measurement. The c axis variation of B03-NMC 811 cathode between 3.7 V and 4.3 V was reduced by 7.6% (0.014 Å) as compared to the pristine one. However, larger quantity (5.0 at%) of boron degrades the electrochemical performance induced by increased Li/Ni disorder. Thereafter, this enhancement in both electrochemical performance and structural stability benefits from the optimized interplanar space between transition metal oxide (003) layers, which can be tuned precisely by such a simple but novel co-sintering process with boric acid. This approach opens the door to structural modification and optimization of NMC811 cathode to satisfy the demanding performance and safety requirements of electric vehicles. [ABSTRACT FROM AUTHOR]

Atmospheric pressure Ar/N 2 binary plasma jet irradiation has been introduced into the manufacturing process of lithium ions batteries as a facile, green and scalable post-fabrication treatment approach, which enhanced significantly the high-rate anode performance of lithium titanate (Li 4 Ti 5 O 12 ). Main emission lines in Ar/N 2 plasma measured by optical emission spectroscopy reveal that the dominant excited high-energy species in Ar/N 2 plasma are N 2 *, N 2 + , N ∗ and Ar ∗ . Sufficient oxygen vacancies have been evidenced by high resolution X-ray photoelectron spectroscopy analysis and Raman spectra. Nitrogen doping has been achieved simultaneously by the surface reaction between pristine Li 4 Ti 5 O 12 particles and chemically reactive plasma species such as N ∗ and N 2 + . The variety of Li 4 Ti 5 O 12 particles on the surface of electrodes after different plasma processing time has been examined by grazing incident X-Ray diffraction. Electrochemical impedance spectra (EIS) confirm that the Ar/N 2 atmospheric plasma treatment facilitates Li + ions diffusion and reduces the internal charge-transfer resistance. The as-prepared Li 4 Ti 5 O 12 anodes exhibit a superior capacity (132 mAh g −1 ) and excellent stability with almost no capacity decay over 100 cycles under a high C rate (10C). [ABSTRACT FROM AUTHOR]