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Electrochemical energy storage devices with both high energy density and high power density are technologically necessary for the electrification of transportation and many other applications. This dissertation focuses on the development of fast-charging Li-ion batteries through a fundamental understanding of structural parameters that allow for fast and reversible redox reactions in electrode materials. Using solution-based routes, the atomic and nanoscale structure of electrode materials was controlled and connected to their electrochemical characteristics, including specific capacity, rate capability, and cycling longevity. Additionally, advanced in operando characterization techniques were employed to probe how materials' structure and properties evolve during cycling. Overall, these findings provide guiding principles for the design of fast-charging electrode materials going forward. The first two sections focus on size-dependent phase transition behavior in MoO2, a model tunnel structure anode (Chapters 2 and 3). Chapter 2 shows how the large first-order phase transition in bulk MoO2 becomes systematically suppressed in a series of size controlled nanoarchitectures. The phase transition remains first-order, but shrinks dramatically, in intermediate-sized nanoporous MoO2 and becomes entirely continuous solid-solution in smaller MoO2 nanocrystals. Accordingly, the signatures of slowed charge storage from the bulk phase transition disappear in the nanomaterials. In chapter 3, we employ this suite of materials to show that this change phase transition behavior is key to the development of pseudocapacitive properties in nanoscale MoO2 using electrochemical impedance spectroscopy. Chapters 4 and 5 characterize the charge storage properties of V9Mo6O40, which transforms into a disordered rock salt structure during cycling. In chapter 4, the crystal structure of V9Mo6O40 is shown to govern its transformation pathway and resulting morphology compared to a well-studied

A key challenge for energy storage and conversion technologies is finding simple, reliable methods that can identify device failure and prolong lifetime. Lithium plating is a well-known degradation process that prevents Li-ion battery fast charging, which is essential to reduce electric vehicle ‘range anxiety’ and enable emerging technologies such as aerial drones and high-performance portable electronics. The ability to detect the initial onset of lithium plating from easily accessible voltage measurements would greatly improve battery safety and feedback controls modeling. In this work, we first highlight the application of a differential open-circuit voltage analysis (dOCV) to detect when Li plating begins during a single charge for room temperature fast charging. We also show that dOCV can identify the Li plating onset during cycling with sensitivity of 1 mg plated Li per gram graphite, equivalent to 1% of the graphite capacity, indicating that this method has commercial promise for on-line Li detection.Next, we demonstrate the power of simple, accessible, and high-throughput cycling techniques to quantify irreversible Li plating spanning data from over 200 cells. We first observe the effects of energy density, charge rate, temperature, and State-of-Charge (SOC) on lithium plating, use the results to refine mature physics-based electrochemical models, and provide an interpretable empirical equation for predicting the plating onset SOC. We then explore the reversibility of lithium plating and its connection to electrolyte design for preventing irreversible Li accumulation. Finally, we design a method to quantify in-situ Li plating for commercially relevant Graphite|LiNi0.5Mn0.3Co0.2O2 (NMC) cells and compare with results from the experimentally convenient Li|Graphite configuration. The hypotheses and abundant data in this section were generated primarily with equipment universal to the battery researcher, encouraging further development of innovative testing meth

Rechargeable aqueous Zn MnO2 batteries are promising for stationary energy storage because of their high energy density, safety, environmental benignity, and low cost. Conventional gravel MnO2 cathodes have low electrical conductivity, slow ion (de-)insertion, and poor cycle stability, resulting in poor recharging performance and severe capacity fading. To improve the rechargeability of MnO2, strategies have been devised such as depositing micrometer-thick MnO2 on carbon cloth and blending nanostructured MnO2 with additives and binders. The low electrical conductivity of binders and sluggish ion (de)insertion in micrometer-thick MnO2, however, still limit the fastcharging performance. Herein, we have prepared porous carbon fiber (PCF) supported MnO2 cathodes (PCF@MnO2), comprised of nanometer-thick MnO2 uniformly deposited on electrospun block copolymer-derived PCF that have abundant uniform mesopores. The high electrical conductivity of PCF, fast electrochemical reactions in nanometer-thick MnO2, and fast ion transport through porous nonwoven fibers contribute to a high rate capability at high loadings. PCF@MnO2, at a MnO2 loading of 59.1 wt%, achieves a MnO2-based specific capacity of 326 and 184 mAhg(-1) at a current density of 0.1 and 1.0 Ag-1, respectively. Our approach of block copolymer-based PCF as a support for zinc-ion cathode inspires future designs of fastcharging electrodes with other active materials.

Rechargeable aqueous Zn MnO2 batteries are promising for stationary energy storage because of their high energy density, safety, environmental benignity, and low cost. Conventional gravel MnO2 cathodes have low electrical conductivity, slow ion (de-)insertion, and poor cycle stability, resulting in poor recharging performance and severe capacity fading. To improve the rechargeability of MnO2, strategies have been devised such as depositing micrometer-thick MnO2 on carbon cloth and blending nanostructured MnO2 with additives and binders. The low electrical conductivity of binders and sluggish ion (de)insertion in micrometer-thick MnO2, however, still limit the fastcharging performance. Herein, we have prepared porous carbon fiber (PCF) supported MnO2 cathodes (PCF@MnO2), comprised of nanometer-thick MnO2 uniformly deposited on electrospun block copolymer-derived PCF that have abundant uniform mesopores. The high electrical conductivity of PCF, fast electrochemical reactions in nanometer-thick MnO2, and fast ion transport through porous nonwoven fibers contribute to a high rate capability at high loadings. PCF@MnO2, at a MnO2 loading of 59.1 wt%, achieves a MnO2-based specific capacity of 326 and 184 mAhg(-1) at a current density of 0.1 and 1.0 Ag-1, respectively. Our approach of block copolymer-based PCF as a support for zinc-ion cathode inspires future designs of fastcharging electrodes with other active materials.

The freight transport plays an important role in the development of the economy. However, this comes with an important contribution to greenhouse gas emission. Recently a shift toward heavy-duty electric vehicles has been made, but some issues still need to be tackled. One of them is to develop ways to quickly recharge the vehicle’s batteries without damaging them. In this thesis, we highlight that not only the current but also the battery temperature need to be carefully managed in order to prevent damages during a charging session. To show that, an electrical, thermal and aging model of Li-ion battery is developed. A charging strategy based on a Model Predictive Control algorithm is proposed. The algorithm controls both the battery current and cooling system in order to achieve the optimal balance between the charging speed and the preservation of the battery. The resulting algorithm is tested, in simulation, against a conventional constant current charging in different charging scenarios. The results show an important increase in performance and highlight the role of the battery cooling system in the preservation of the battery., Godstransporterna spelar en viktig roll för ekonomins utveckling. Detta innebär dock ett betydande bidrag till utsläppen av växthusgaser. På senare tid har en övergång till tunga elfordon skett, men vissa frågor måste fortfarande lösas. En av dem är att utveckla metoder för att snabbt ladda fordonsbatterierna utan att skada dem. I den här avhandlingen lyfter vi fram att inte bara strömmen utan även batteritemperaturen måste hanteras noggrant för att förhindra skador under en laddning. För att visa detta utvecklas en elektrisk, termisk och åldrande modell för Li-ion-batterier. En laddningsstrategi baserad på en algoritm för modellförutsägbar styrning föreslås. Algoritmen styr både batteriströmmen och kylsystemet för att uppnå en optimal balans mellan laddningshastighet och bevarande av batteriet. Den resulterande algoritmen testas i simulering mot en konventionell konstantström laddning i olika laddningsscenarier. Resultaten visar en betydande ökning av prestanda och belyser batterikylsystemets betydelse för bevarandet av batteriet.

The freight transport plays an important role in the development of the economy. However, this comes with an important contribution to greenhouse gas emission. Recently a shift toward heavy-duty electric vehicles has been made, but some issues still need to be tackled. One of them is to develop ways to quickly recharge the vehicle’s batteries without damaging them. In this thesis, we highlight that not only the current but also the battery temperature need to be carefully managed in order to prevent damages during a charging session. To show that, an electrical, thermal and aging model of Li-ion battery is developed. A charging strategy based on a Model Predictive Control algorithm is proposed. The algorithm controls both the battery current and cooling system in order to achieve the optimal balance between the charging speed and the preservation of the battery. The resulting algorithm is tested, in simulation, against a conventional constant current charging in different charging scenarios. The results show an important increase in performance and highlight the role of the battery cooling system in the preservation of the battery., Godstransporterna spelar en viktig roll för ekonomins utveckling. Detta innebär dock ett betydande bidrag till utsläppen av växthusgaser. På senare tid har en övergång till tunga elfordon skett, men vissa frågor måste fortfarande lösas. En av dem är att utveckla metoder för att snabbt ladda fordonsbatterierna utan att skada dem. I den här avhandlingen lyfter vi fram att inte bara strömmen utan även batteritemperaturen måste hanteras noggrant för att förhindra skador under en laddning. För att visa detta utvecklas en elektrisk, termisk och åldrande modell för Li-ion-batterier. En laddningsstrategi baserad på en algoritm för modellförutsägbar styrning föreslås. Algoritmen styr både batteriströmmen och kylsystemet för att uppnå en optimal balans mellan laddningshastighet och bevarande av batteriet. Den resulterande algoritmen testas i simulering mot en konventionell konstantström laddning i olika laddningsscenarier. Resultaten visar en betydande ökning av prestanda och belyser batterikylsystemets betydelse för bevarandet av batteriet.

Rechargeable aqueous Zn MnO2 batteries are promising for stationary energy storage because of their high energy density, safety, environmental benignity, and low cost. Conventional gravel MnO2 cathodes have low electrical conductivity, slow ion (de-)insertion, and poor cycle stability, resulting in poor recharging performance and severe capacity fading. To improve the rechargeability of MnO2, strategies have been devised such as depositing micrometer-thick MnO2 on carbon cloth and blending nanostructured MnO2 with additives and binders. The low electrical conductivity of binders and sluggish ion (de)insertion in micrometer-thick MnO2, however, still limit the fastcharging performance. Herein, we have prepared porous carbon fiber (PCF) supported MnO2 cathodes (PCF@MnO2), comprised of nanometer-thick MnO2 uniformly deposited on electrospun block copolymer-derived PCF that have abundant uniform mesopores. The high electrical conductivity of PCF, fast electrochemical reactions in nanometer-thick MnO2, and fast ion transport through porous nonwoven fibers contribute to a high rate capability at high loadings. PCF@MnO2, at a MnO2 loading of 59.1 wt%, achieves a MnO2-based specific capacity of 326 and 184 mAhg(-1) at a current density of 0.1 and 1.0 Ag-1, respectively. Our approach of block copolymer-based PCF as a support for zinc-ion cathode inspires future designs of fastcharging electrodes with other active materials.

Rechargeable aqueous Zn MnO2 batteries are promising for stationary energy storage because of their high energy density, safety, environmental benignity, and low cost. Conventional gravel MnO2 cathodes have low electrical conductivity, slow ion (de-)insertion, and poor cycle stability, resulting in poor recharging performance and severe capacity fading. To improve the rechargeability of MnO2, strategies have been devised such as depositing micrometer-thick MnO2 on carbon cloth and blending nanostructured MnO2 with additives and binders. The low electrical conductivity of binders and sluggish ion (de)insertion in micrometer-thick MnO2, however, still limit the fastcharging performance. Herein, we have prepared porous carbon fiber (PCF) supported MnO2 cathodes (PCF@MnO2), comprised of nanometer-thick MnO2 uniformly deposited on electrospun block copolymer-derived PCF that have abundant uniform mesopores. The high electrical conductivity of PCF, fast electrochemical reactions in nanometer-thick MnO2, and fast ion transport through porous nonwoven fibers contribute to a high rate capability at high loadings. PCF@MnO2, at a MnO2 loading of 59.1 wt%, achieves a MnO2-based specific capacity of 326 and 184 mAhg(-1) at a current density of 0.1 and 1.0 Ag-1, respectively. Our approach of block copolymer-based PCF as a support for zinc-ion cathode inspires future designs of fastcharging electrodes with other active materials.

Demand for electric vehicles (EVs), and thus EV charging, has steadily increased over the last decade. Studies suggest that fast-charging facilities are crucial for the EV market. However, there is limited fast-charging infrastructure in most parts of the world to support EV travel, especially long-distance trips. The goal of this study is to develop a stochastic dynamic simulation modeling framework of a regional system of EV fast-charging stations for real-time management and strategic planning (i.e., capacity allocation) purposes. To model EV user behavior, specifically fast-charging station choices, the framework incorporates a multinomial logit station choice model that considers station charging prices, expected wait times, and detour distances. To capture the dynamics of supply and demand at each EV fast-charging station, the framework incorporates a multi-server queueing model in the simulation. The study assumes that multiple fast-charging stations are managed by a single entity (public or private) and that the demand for these stations are interrelated (through the station choice model). To manage the system of stations, this study proposes and tests dynamic demand-responsive price adjustment (DDRPA) schemes based on station queue lengths. The study applies the modeling framework to a system of EV fast-charging stations in Southern California. The computational results indicate that DDRPA strategies are an effective mechanism to balance charging demand across fast-charging stations. Specifically, compared to the no DDRPA scheme case, the quadratic DDRPA scheme reduces average wait time by 26%, increases charging station revenue (and user costs) by 5.8%, while, most importantly, increasing social welfare by 2.7% in the base scenario. Moreover, the study also illustrates that the modeling framework can evaluate the allocation of EV fast-charging station capacity, to identify stations that require additional chargers and areas that would benefit from addition

To solve the problems of fast-charging of lithium-ion batteries in essence, development of new electrode materials with higher lithium-ion diffusion coefficients is the key. In this work, a novel flower-like Ni@SnNi structure is synthesized via a two-step process design, which consists of the fabrication of Ni cores by spray pyrolysis followed by the formation of SnNi shells via a simple oxidation-reduction reaction. The obtained Ni@SnNi composite exhibits an initial capacity of approximate to 693 mA h g(-1) and a reversible capacity of approximate to 570 mA h g(-1) after 300 charge/discharge cycles at 0.5 C, and maintains 450 mA h g(-1) even at a high rate of 3 C. Further, it is proved that a Ni@SnNi composite possesses high lithium-ion diffusion coefficient (approximate to 10(-8)), which is much higher than those (approximate to 10(-10)) reported previously, which can be mainly attributed to the unique flower-like Ni@SnNi structure. In addition, the full cell performance (Ni@SnNi-9h/graphite vs LiCoO2) with a capacity ratio of 1.13 (anode/cathode) is also tested. It is found that even at 2 C rate charging/discharging, the capacity retention at 100 cycles is still close to 89%. It means that Ni@SnNi-9h is a promising anode additive for lithium-ion batteries with high energy density and power density.

To solve the problems of fast-charging of lithium-ion batteries in essence, development of new electrode materials with higher lithium-ion diffusion coefficients is the key. In this work, a novel flower-like Ni@SnNi structure is synthesized via a two-step process design, which consists of the fabrication of Ni cores by spray pyrolysis followed by the formation of SnNi shells via a simple oxidation-reduction reaction. The obtained Ni@SnNi composite exhibits an initial capacity of approximate to 693 mA h g(-1) and a reversible capacity of approximate to 570 mA h g(-1) after 300 charge/discharge cycles at 0.5 C, and maintains 450 mA h g(-1) even at a high rate of 3 C. Further, it is proved that a Ni@SnNi composite possesses high lithium-ion diffusion coefficient (approximate to 10(-8)), which is much higher than those (approximate to 10(-10)) reported previously, which can be mainly attributed to the unique flower-like Ni@SnNi structure. In addition, the full cell performance (Ni@SnNi-9h/graphite vs LiCoO2) with a capacity ratio of 1.13 (anode/cathode) is also tested. It is found that even at 2 C rate charging/discharging, the capacity retention at 100 cycles is still close to 89%. It means that Ni@SnNi-9h is a promising anode additive for lithium-ion batteries with high energy density and power density.

In this study, we introduce a battery energy storage system (BESS) with reconfigurable cell topology as the direct power source for fast-charging of electric vehicles (EVs). In the proposed scenario, the BESS is following the charging request of the EV by changing its cell topology in a real time fashion. The BESS is modelled at the cell level in order to demonstrate the reconfigurable design, and linked with an EV model. The simulation results confirm that the BESS can maintain a balanced level of its cell states while following the voltage request of the EV with satisfactory precision. However, the approach of adaptive cell switching shows to be not sufficient for fulfilling the current request. Therefore, complementary solutions are necessary to achieve a suitable control of the charging current

At electric vehicle fast-charging stations, it is generally recommended to avoid charging beyond similar to 80% State-of-Charge (SOC) since topping-off to full capacity disproportionately increases the charging time. This necessitates studying its long-term impact compared to slower rate charging to full capacity typical of home or residential charging. Here we present the long-term ageing effects on commercial 18650 NMC-LMO/graphite cell cycled between 2.6-4.2 V at three different charging protocols: 1.5 C-rate fast-partial charging ( to 82.5% SOC), 0.5 C-rate slow standard charging without or with a constant-voltage step (to 93% or 100% SOC). Quantitative discharge-curve and postmortem analyses are used to evaluate ageing. The results show that ageing rate increases in the order: fast-partial charging < standard charging < standard charging with constant-voltage period, indicating that higher SOC-range near full capacity is more detrimental to battery life than fast-charging. The capacity fade is totally dominated by cyclable-lithium loss. The similar to 8% NMC-LMO active material loss has negligible impact on the cell capacity fade due to the electrodes excess material in the fresh cell and its moderate loss rate with ageing compared to the cyclable-lithium. Similar ageing modes in terms of capacity fade and impedance rise are found irrespective of the charging protocol., QC 20171222