Grid-scale Energy Storage Systems Research Articles

Spherical Shell with CNTs Network Structuring Fe-Based Alluaudite Na2+2 δ Fe2- δ (SO4 )3 Cathode and Novel Phase Transition Mechanism for Sodium-Ion Battery.

Iron-based sulfate cathodes of alluaudite Na2+2 δ Fe2- δ (SO4 )3 (NFS) in sodium-ion batteries with low cost, steady cycling performance, and high voltage are promising for grid-scale energy storage systems. However, the poor electronic conductivity and the limited understanding of the phase-evolution of precursors hinder obtaining high-rate capacity and the pure phase. Distinctive NFS@C@n%CNTs (n = 1, 2, 5, 10) sphere-shell conductive networks composite cathode materials are constructed creatively, which exhibit superior reversible capacity and rate performance. In detail, the designed NFS@C@2%CNTs cathode delivers an initial discharge capacity of 95.9 mAh g-1 at 0.05 C and up to 60 mAh g-1 at a high rate of 10 C. The full NFS@C@2%CNTs//HC cell delivers a practical operating voltage of 3.5V and mass-energy density of 140Wh kg-1 at 0.1 C, and it can also retain 67.37 mAh g-1 with a capacity retention rate of 96.4% after 200 cycles at 2 C. On the other hand, a novel combination reaction mechanism is first revealed for forming NFS from the mixtures of Na2 Fe(SO4 )2 ·nH2 O (n = 2, 4) and FeSO4 ·H2 O during the sintering process. The inspiring results would provide a novel perspective to synthesize high-performance alluaudite sulfate and analogs by aqueous methods.

Large-scale energy storage system: safety and risk assessment

The International Renewable Energy Agency predicts that with current national policies, targets and energy plans, global renewable energy shares are expected to reach 36% and 3400 GWh of stationary energy storage by 2050. However, IRENA Energy Transformation Scenario forecasts that these targets should be at 61% and 9000 GWh to achieve net zero carbon emissions by 2050 and limit the global temperature rise within the twenty-first century to under 2 °C. Despite widely known hazards and safety design of grid-scale battery energy storage systems, there is a lack of established risk management schemes and models as compared to the chemical, aviation, nuclear and the petroleum industry. Incidents of battery storage facility fires and explosions are reported every year since 2018, resulting in human injuries, and millions of US dollars in loss of asset and operation. Traditional risk assessment practices such as ETA, FTA, FMEA, HAZOP and STPA are becoming inadequate for accident prevention and mitigation of complex energy power systems. This work describes an improved risk assessment approach for analyzing safety designs in the battery energy storage system incorporated in large-scale solar to improve accident prevention and mitigation, via incorporating probabilistic event tree and systems theoretic analysis. The causal factors and mitigation measures are presented. The risk assessment framework presented is expected to benefit the Energy Commission and Sustainable Energy Development Authority, and Department of Standards in determining safety engineering guidelines and protocols for future large-scale renewable energy projects. Stakeholders and Utility companies will benefit from improved safety and reliability by avoiding high-cost asset damages and downtimes due to accident events.

Synthesis-Driven Computational Discovery of Organic Redoxmers for Non-Aqueous Redox Flow Batteries

Organic non-aqueous redox flow batteries (RFBs) are promising grid-scale energy storage systems for storing intermittent renewable energy in molecules. For practical applications, low-cost and stable redox active molecules (redoxmers) that display a large redox potential window and long electrochemical cycling stability are required to deliver a high-energy-density RFB with a long battery cycle life. To accelerate the discovery of redoxmer molecules, previous studies have utilized machine learning (ML) methods along with first-principles simulations. Although many ML-suggested molecules show promising electrochemical properties, they are generally difficult to synthesize because of their highly complex structure. To address this challenge, in this work, we propose a new synthesis-driven computational approach to discovering less-complex molecules with a large redox potential window that can deliver high-energy-density RFBs. Specifically, we devised an algorithm to generate an engineered molecular search space and applied a Bayesian optimization-based active learning algorithm to discover promising molecules from a large molecular search space while using a limited number of expensive density functional theory (DFT) calculations. To increase the energy density of RFBs, we focus on maximizing the redox potential window of redoxmer molecules (or cell voltage) by minimizing the reduction potential of anolyte molecules. Precisely, we studied the 2,1,3 Benzothiadiazole (BTZ) molecule, a promising anolyte (redoxmer) candidate for RFBs, and with our synthesis-driven approach discovered new BTZ-based molecules that show 15-43% smaller reduction potential than the BTZ and in principle can deliver organic RFBs with a cell voltage ≈ 3 V.

Development of Membranes and Separators to Inhibit Cross-Shuttling of Sulfur in Polysulfide-Based Redox Flow Batteries: A Review.

The global rapid transition from fossil fuels to renewable energy resources necessitates the implementation of long-duration energy storage technologies owing to the intermittent nature of renewable energy sources. Therefore, the deployment of grid-scale energy storage systems is inevitable. Sulfur-based batteries can be exploited as excellent energy storage devices owing to their intrinsic safety, low cost of raw materials, low risk of environmental hazards, and highest theoretical capacities (gravimetric: 2600 Wh/kg and volumetric: 2800 Wh/L). However, sulfur-based batteries exhibit certain scientific limitations, such as polysulfide crossover, which causes rapid capacity decay and low Coulombic efficiency, thereby hindering their implementation at a commercial scale. In this review article, we focus on the latest research developments between 2012-2023 to improve the separators/membranes and overcome the shuttle effect associated with them. Various categories of ion exchange membranes (IEMs) used in redox batteries, particularly polysulfide redox flow batteries and lithium-sulfur batteries, are discussed in detail. Furthermore, advances in IEM constituents are summarized to gain insights into different fundamental strategies for attaining targeted characteristics, and a critical analysis is proposed to highlight their efficiency in mitigating sulfur cross-shuttling issues. Finally, future prospects and recommendations are suggested for future research toward the fabrication of more effective membranes with desired properties.

Constructing Pure Si Anodes for Advanced Lithium Batteries.

ConspectusWith the escalating demands of portable electronics, electric vehicles, and grid-scale energy storage systems, the development of next-generation rechargeable batteries, which boasts high energy density, cost effectiveness, and environmental sustainability, becomes imperative. Accelerating these advancements could substantially mitigate detrimental carbon emissions. The pursuit of main objectives has kindled interest in pure silicon as a high-capacity electroactive material, capable of further enhancing the gravimetric and volumetric energy densities compared with traditional graphite counterparts. Despite such promising attributes, pure silicon materials face significant hurdles, primarily due to their drastic volumetric changes during the lithiation/delithiation processes. Volume changes give rise to severe side effects, such as fracturing, pulverization, and delamination, triggering rapid capacity decay. Therefore, mitigating silicon particle fracture remains a primary challenge. Importantly, nanoscale silicon (below 150 nm in size) has shown resilience to stresses induced by repeated volume changes, thereby highlighting its potential as an anode-active material. However, the volume expansion stress not only affects the internal structure of the particle but also disrupts the solid-electrolyte interphase (SEI) layer, formed spontaneously on the outer surface of silicon, causing adverse side reactions. Therefore, despite silicon nanoparticles offering new opportunities, overcoming the associated issues is of paramount importance.Thus, this Account aims to spotlight the significant strides made in the development of pure silicon anodes with particular attention to feature size. From the emergence of nanoscale silicon, the following nanotechnology played a crucial role in growing the particle through nano/microstructuring. Similarly, bulk silicon microparticles gradually surfaced with the post-engineering methods owing to their practical advantages. We briefly discuss the special characteristics of representative examples from bulk silicon engineering and nano/microstructuring, all aimed at overcoming intrinsic challenges, such as limiting large volume changes and stabilizing SEI formation during electrochemical cycling. Subsequently, we outline guidelines for advancing pure silicon anodes to incorporate high mass loading and high energy density. Importantly, these advancements require superior material design and the incorporation of exceptional battery components to ensure compatibility and yield synergistic effects. By broadening the cooperative strategies at the cell and system levels, we anticipate that this Account will provide an insightful analysis of pure silicon anodes and catalyze their practical applications in real battery systems.

Applications and Challenges of Lithium-Sulfur Electrochemical Batteries

<p>This paper presents applications of lithium-sulfur (Li-S) energy storage batteries, while showing merits and demerits of several techniques to mitigate their electrochemical challenges. Unmanned aerial vehicles, electric cars, and grid-scale energy storage systems represent main applications of Li-S batteries due to their low cost, high specific capacity, and light weight. However, polysulfide shuttle effects, low conductivities, and low coulombic efficiencies signify key challenges of Li-S batteries, causing high volumetric changes, dendritic growths, and limited cycling performances. Solid-state electrolytes, interfacial interlayers, and electrocatalysts denote promising methods to mitigate such challenges. Moreover, nanomaterials have capability to improve kinetic reactions of Li-S batteries based on several properties of nanoparticles to immobilize sulfur in cathodes, stabilizing lithium in anodes while controlling volumetric growths. Li-S energy storage technologies are able to satisfy requirements of future markets for advanced rechargeable batteries with high-power densities and low costs, considering environmentally friendly systems based on renewable energy sources.</p>

Comparing Sodium-ion Battery Electrode Materials in the Scope of Grid-Scale Batteries supporting Renewable Energy Sources and Future Electrification Demands

With current emission outputs from electricity generation, multiple stakeholders seek to decarbonize and transform current energy grid technology and energy generators. In support of this transition, this paper analyzes the technological capabilities of current grid-scale level energy storage systems and provides a process of prioritizing electrode material qualities. In specific, this paper explores anode and cathode materials for Sodium-ion batteries utilizing attributes oriented for energy grid usage. This paper proposes the weighted-ranking system considering factors of reversible capacity, energy density, cycling ability, and material abundance. This paper seeks to aid those researching future electrode materials for SIBs in the context of future grid-scale level batteries through contextualizing various electrode materials in comparison. This paper also seeks to provide a valid method of comparing multiple electrode materials to recommend specific research and development areas.

Sodium-rich prussian blue analogue coated by poly(3,4-ethylenedioxythiophene) polystyrene sulfonate as superior cathode for sodium-ion batteries

Sodium-ion batteries (SIBs) are a promising alternative to complement costly lithium-ion batteries for grid-scale stationary energy storage systems. However, finding a suitable cathode material has been a challenging process mainly due to the large radius of sodium-ion that hinders the process of intercalation. In our previous work, we have successfully synthesized Prussian blue analogue (PBA) via simple single iron source precipitation and low thermal method. However, it suffered poor electrical conductivity. In this work, the as-prepared PBA (high purity, low vacancy (∼2%), and high sodium-ion content) was then coated with various concentrations of conductive polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT-PSS) via simple stirring method to aid the electron route. The coated PBA (PB–P5) demonstrates two-fold enhanced conductivity of 2.04 × 10−5 S cm−1 at 30 °C and 1.18 × 10−4 S cm−1 at 100 °C. XRD peaks of coated PBAs show a slight shifting to higher diffraction angle, indicating the changes from rhombohedral-like to cubic structure. The battery capacity retention has also improved from 73.9% (PB–P0) to 82.87% (PB–P5), on account of having PEDOT-PSS to slow down the side reaction between cathode and electrolyte and eventually improve the cycling stability. Additionally, PB-P5 displays the lowest potential separation in cyclic voltammetry (CV) and small charge transfer resistance, Rct value, in which indicating a better electron transfer and enhanced overall conductivity.

Design of ultrathin carbon-wrapped lithium vanadium phosphate nanoparticles as cathodes for high-performance lithium-ion batteries

Lithium vanadium phosphate (LVP) is a commonly used cathode material due to its high energy density, low voltage fade, and stability, making it suitable for use in electric vehicles, portable electronic devices, and grid-scale energy storage systems. However, LVP does have some limitations, including temperature sensitivity and lower efficiency compared to certain other cathode materials. Herein, a carbon-modified LVP (LVP/C) composite is designed for lithium-ion battery cathode materials. The uniquely designed LVP/C demonstrates a flake-like and high-crystal structure LVP with ultra-thin 6 nm carbon coating. On the one hand, highly crystalline LVP can provide stable active sites, and on the other hand, the ultrathin 6 nm carbon-coated sheet-like structure can not only alleviate the volume expansion but also avoid agglomeration. As expected, the specific capacities of the LVP/C-150 and LVP/C-180 samples are found to be 120.535 mAh/g and 35.586 mAh/g at a current rate of 0.5 C, respectively. The LVP/C-150 sample exhibites improved rate performance and cycling stability compared to the LVP/C-180 sample. The outstanding electrochemical performance can be attributed to nanostructure, amorphous carbon, and 6 nm ultra-thin carbon coating. Furthermore, our results suggest that the LVP/C-150 sample has a higher lithium-ion insertion/extraction capacity, which contributes to its improved electrochemical performance.

Enroute to sub-300 °C operating Sn–Zn||Pb–Bi liquid metal battery by compositional engineering

Liquid metal battery (LMB) is considered a potential contender for grid-scale energy storage systems. However, high operating temperatures (>400 °C) leading to higher operational costs limit its commercial application. Therefore, the current work focuses on reducing the melting temperature of electrodes and electrolytes below 300 °C by compositional engineering. Moreover, this study utilizes earth-abundant elements like Zn (with less reliance on Li), in Zn–Sn||Bi–Pb LMB system. The composition of LiCl in the electrolyte is varied to optimize the battery performance, especially the energy efficiency and overpotential while maintaining an operating temperature of <275 °C. It is found that as the LiCl content in the electrolyte salt increases (5–30 Mol%), the overpotential of the battery decreases (0.9–0.3 V), and the energy efficiency of the charge-discharge process improves (14.5%–80.9%) owing to the better ionic conductivity of LiCl. For the optimized LiCl concentration of 30 Mol% LiCl in the electrolyte, the fabricated LMB exhibit good cyclability (no degradation till 100 cycles), a high discharging voltage plateau of 0.92 V, 24.6 mAh charge storage capacity, and a low operating temperature of 275 °C, which is the lowest operating temperature reported so far in a Zn-based LMB system.

Nitrogen as An Anionic Center/Dopant for Next‐Generation High‐Performance Lithium/Sodium‐Ion Battery Electrodes: Key Scientific Issues, Challenges and Perspectives

AbstractThe rapid progress of lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs) have extensively promoted the rechargeable battery technology in the fields of electric vehicles and grid scale energy storage systems. With recent highly effective nitrogen doping strategy in terms of improving the overall electrochemical performance in various sorts of battery systems, the bulk N doping/substitution lays on the core innovations toward structural manipulation toward higher ionic conductivity, elevated reversible working plateau, etc. However, the key scientific and practical issues such as the phase formation process, phase transition kinetics, valence change and anionic/cationic physical/chemical behaviors still leave open questions in the direction of their real applications in the next‐generation battery technology. In light of this, a timely and in‐depth perspective is provided on the development of the bulk N doping/substitution strategy of these high‐performance electrodes of LIBs/SIBs adapting nitrogen as anionic center/dopant. Both the variations of phase and structural constitutions, alkali ion storage mechanism, electrochemical change, and the alkali ion kinetics, which are the key scientific parts for the future explorations of these novel and promising electrodes are highlighted. The most urgent and critical commercial obstacles or challenges towards cost‐efficiency synthetic approach without excessive environmental pollutions are also outlined. With the participation of nitrogen in bulk crystals , the overall specific energy density of next‐generation alkali ion batteries will be reasonably promoted and accelerated in the near future.

Guest editorial: Application of cloud energy storage systems in power systems

Guest editorial: Application of cloud energy storage systems in power systems

Distribution locational marginal price based hierarchical scheduling framework for grid flexibility from virtual energy storage systems

• VESS's are modeled using residential air-conditioners for DSM. • Local ancillary services TSO-DSO coordination scheme for cooperative management in grids. • Hierarchical framework for scheduling aggregated VESS. • Network constrained optimal VESS participation in ancillary service markets. • DSM based practical market model for SOs, maximizing overall market benefits. Maintaining generation and demand equilibrium under large scale renewable energy integration is challenging. Conventional flexibility providers such as grid-scale Energy Storage Systems (ESS) have potential but are costly solutions. With evolving smart grid scenario, aggregated demand response from Thermostatically Controlled Loads (TCLs) is utilized as Virtual Energy Storage Systems (VESS) and considered as innovative and cost efficient solution to provide fast response reserves. VESS units are often scheduled and controlled in a centralized manner considering limited distribution system constraints. However, accurate operational flexibility potential of diversified VESS units for various grid services needs to consider distribution network constraints. It can be fully utilized when Distribution System Operators (DSO) coordinate with Transmission System Operators (TSO) to transfer grid services from VESS of its area. Local ancillary service TSO-DSO coordination scheme ensures in this perspective significant flexibility of TSO and allows both TSO and DSO to access VESS flexibility. For such controlling of diversified VESS units where DSO is responsible for aggregate flexibility and local area balancing, a hierarchical scheduling framework is more practical. In this context, this paper proposes a two-stage hierarchical approach for optimal scheduling of TCLs as VESS to optimize energy and provide grid flexibility. At the lower stage, TCLs are scheduled based on Distribution Locational Marginal Price (DLMP) provided by DSO, while ensuring consumers’ comfort. At the upper level, DSO provides additional flexibility to TSO through optimal scheduling of aggregated VESS considering local ancillary services TSO-DSO coordination scheme. The simulation results indicate that VESS scheduling improves system flexibility by maintaining a generation-demand balance.

Building Na-ion full cells using homologous Prussian blue and its phosphide derivative

Due to their low production cost and rich resource availability, Na-ion batteries have emerged as the best option for grid-scale energy storage systems. Nonetheless, the commercialization of Na-ion batteries has been hampered by a shortage of acceptable anode and cathode materials. In this work, we report a superior Na-ion full cell constructed using a homologous Prussian blue (PB) cathode and its derived core–shell FeP@C anode. The PB cathode delivers a discharge capacity of 111 mAh/g and a prominent lifetime of 2000 loops with 99.7% capacity retention. Additionally, the FeP@C anode manifests a reversible capacity of 368.4 mAh/g and an outstanding rate capability of 111.1 mAh/g at 20 A/g. When assembled into a Na-ion full cell, a remarkable discharge capacity of 108.3 mAh/g with steady-state cyclic behavior is achieved. This homologous design strategy is expected to provide an alternative possibility for constructing high-performance Na-ion full cells.

Doping Regulation in Polyanionic Compounds for Advanced Sodium-Ion Batteries.

It has long been the goal to develop rechargeable batteries with low cost and long cycling life. Polyanionic compounds offer attractive advantages of robust frameworks, long-term stability, and cost-effectiveness, making them ideal candidates as electrode materials for grid-scale energy storage systems. In the past few years, various polyanionic electrodes have been synthesized and developed for sodium storage. Specifically, doping regulation including cation and anion doping has shown a great effect in tailoring the structures of polyanionic electrodes to achieve extraordinary electrochemical performance. In this review, recent progress in doping regulation in polyanionic compounds as electrode materials for sodium-ion batteries (SIBs) is summarized, and their underlying mechanisms in improving electrochemical properties are discussed. Moreover, challenges and prospects for the design of advanced polyanionic compounds for SIBs are put forward. It is anticipated that further versatile strategies in developing high-performance electrode materials for advanced energy storage devices can be inspired.

Impact of the splitting of the German–Austrian electricity bidding zone on investment in a grid-scale battery energy storage system deployed for price arbitrage with gray and green power in Austrian and German day-ahead power markets

The splitting of the German–Austrian electricity bidding zone in October 2018 established limits for cross-border exchanges of power between Germany and Austria, which led to the decoupling of German and Austrian wholesale power prices. We analyze the impact of the split on the investment in lithium-ion grid-scale battery energy storage systems (BESS) used for intertemporal arbitrage in German and Austrian day-ahead power markets with hourly contracts operated by the Energy Exchange of Austria. The paper was written in response to the increasing share of green power in the national energy mix of the two countries, followed by a similar development in the volume of green power traded. Arbitrage with green power was analyzed and compared to arbitrage with power from conventional sources using a robust mixed-integer linear programming (MILP) model extended with a battery degradation process. The model was solved for different levels of depth of discharge (DOD) to identify the optimum between cycle life and calendar aging with respect to prevailing market conditions. Using predicted costs of battery, a break-even point was reached with 60% DOD identified as the optimal pattern for the dispatch of the BESS. A separate scenario was considered for the analysis of the impact of moving from the perfect knowledge of future prices to a situation where day-ahead prices are forecasted using the seasonal autoregressive integrated moving average (SARIMA) model.

Releasing plating-induced stress for highly reversible aqueous Zn metal anodes

Rechargeable aqueous zinc-ion batteries (ZIBs) have become one of the most potential technologies for grid-scale energy storage systems. The practical application, however, has been severely plagued by the uncontrollable dendrite growth and side reactions on ZIB anodes with planar structure, making it urgent to develop efficient strategies to stabilize Zn anodes. Herein, it is revealed that the Zn dendrite growth is strongly associated with the internal stress accumulation during Zn plating. Moreover, a Zn metal anode with patterned micro-grooves structure that can effectively release the plating-induced stress and inhibit the dendrite growth. Notably, the groove-patterned Zn anodes coupling with Nafion film coating could effectively depress the side reactions and present ultra-stable cycling over 1200 h at a high current density of 10 mA cm−2, a low electrochemical polarization for the rate performance range from 1 to 20 mA cm−2 as well as a stable voltage hysteresis in deep discharge/charge performance at 10 mA cm−2 and 10 mAh cm−2. The feasibility of the proposed strategy is further confirmed and implemented in the Zn|MnO2 flexible pouch cell which delivers an impressive capacity of 186 mAh g−1, high electrochemical stability, and outstanding mechanical flexibility. The finding of this study is expected to provide a deep insight into the design of highly reversible aqueous Zn-ion batteries.

Flexible PEDOT:PSS nanopapers as “anion-cation regulation” synergistic interlayers enabling ultra-stable aqueous zinc-iodine batteries

Aqueous zinc-iodine (Zn-I2) batteries are promising candidates for low-cost grid-scale energy storage systems. However, the long-term stability and energy density of the Zn-I2 batteries are largely hindered by the lack of feasible and scalable methods that coherently suppress polyiodide shuttling and Zn dendrites growth, especially at high current densities. Herein, a flexible, thin and lightweight poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) nanopaper is designed as an “anion-cation regulation” synergistic interlayer to tackle the above issues. The PEDOT:PSS interlayer exhibits a 3D nanofibrous network with uniformly distributed mesopores, abundant polar groups and intrinsic conductivity, which renders an even Zn2+ flux at Zn anode and facilitates homogeneous current distributions at I2 cathode. Meanwhile, such interlayer can act as physiochemical shield to enhance the utilization of I2 cathode via the coulombic repulsion and chemical adsorption effect against polyiodide shuttling. Thus, long-term dendrite-free Zn plating/stripping is achieved at simultaneous high current density and high areal capacity (550 h at 10 mA cm−2/5 mAh cm−2). Zn-I2 batteries harvest a high capacity (230 mAh g−1 at 0.1 A g−1) and an ultralong lifespan (>20000 cycles) even at 10 A g−1. This work demonstrates the potential use of the multifunctional interlayers for Zn-I2 battery configuration innovation by synergistic regulation of cations and anions at the electrodes/electrolyte interface.

An artificial zinc phosphide interface toward stable zinc anodes

Rechargeable aqueous zinc-ion batteries with the characteristics of low cost and high capacity represent a promising device for the grid-scale energy storage system. However, the deleterious dendrite growth and side reactions of the Zn metal anode are hindering its development. Herein, artificial Zn3P2 interphase is constructed on Zn metal to guide rapid and homogeneous Zn deposition via the electrochemical anodic oxidation combined with the phosphating strategy for highly reversible Zn metal batteries. The in-situ construction of artificial interphase could kinetically homogenize Zn nucleation and protect the zinc metal from corrosion and side reactions. As expected, a symmetrical cell with the Zn3P2-armed Zn anode delivers highly reversible Zn plating/stripping with a lifespan of over 1000 h. Moreover, the protected Zn||MnO2 full cells demonstrate remarkable durability with 91.8% capacity retention after 200 cycles. This work paves the way to rationally design artificial interphases for highly reversible aqueous Zn metal batteries.

Operando monitoring of single-particle kinetic state-of-charge heterogeneities and cracking in high-rate Li-ion anodes

To rationalize and improve the performance of newly developed high-rate battery electrode materials, it is crucial to understand the ion intercalation and degradation mechanisms occurring during realistic battery operation. Here we apply a laboratory-based operando optical scattering microscopy method to study micrometre-sized rod-like particles of the anode material Nb14W3O44 during high-rate cycling. We directly visualize elongation of the particles, which, by comparison with ensemble X-ray diffraction, allows us to determine changes in the state of charge of individual particles. A continuous change in scattering intensity with state of charge enables the observation of non-equilibrium kinetic phase separations within individual particles. Phase field modelling (informed by pulsed-field-gradient nuclear magnetic resonance and electrochemical experiments) supports the kinetic origin of this separation, which arises from the state-of-charge dependence of the Li-ion diffusion coefficient. The non-equilibrium phase separations lead to particle cracking at high rates of delithiation, particularly in longer particles, with some of the resulting fragments becoming electrically disconnected on subsequent cycling. These results demonstrate the power of optical scattering microscopy to track rapid non-equilibrium processes that would be inaccessible with established characterization techniques.