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At least 1,297 records · Page 72
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Probing lattice defects in crystalline battery cathode using hard X-ray nanoprobe with data-driven modeling

Lattice defects, e.g., dislocations and grain boundaries, critically impact the properties of crystalline battery cathode materials. A longstanding challenge is to probe the meso–scale heterogeneity and evolution of lattice defects with sensitivity to atomic-scale details. Herein, we tackle this issue with a unique combination of X-ray nanoprobe diffractive imaging and advanced machine learning techniques. The domains with different lattice defect configuration within a single-crystalline LiCoO2 cathode particle are faithfully revealed using our approach. We further visualize the rearrangement of grain boundaries and local crystallinity upon mild thermal annealing. Furthermore, these results pave a direct way to the understanding of crystalline battery materials’ response under external stimuli with high fidelity, which provides valuable empirical guidance to defect-engineering strategies for improving the cathode materials against aggressive battery operation.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Building interface bonding and shield for stable Li-rich Mn-based oxide cathode

Implementation of Li-rich Mn-based oxide cathode with high-energy-density has been restrained by capacity/voltage degradation that results from irreversible lattice oxygen loss and structure rearrangements. To resolve these challenges, in this work, Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 encapsulated by amorphous Co x B (CB-LRM) is rationally designed via autocatalytic plating for highly reversible cationic/anionic hybrid cathode material. Band coherency is ingeniously evoked by interface-reconstruction between bulk structure and amorphous coating layer, which lower the energy of O $2p$ states. Furthermore, this is associated with strengthened orbital hybridization of O $2p$-Mn $3d$ and increased formation energy of oxygen vacancy, which mitigates the lattice oxygen loss considerably. Additionally, interface shielding effects that protect electrode against electrolyte corrosion and the reduction of surface oxygen are also present with fully coverage of amorphous Co x B coating layer. As a result, the as-designed CBLRM cathode exhibits excellent cycle stability after 100 loops with only 0.154% per cycle capacity fade and improved voltage degradation. Given this, this work provides a potential avenue for rational design of lattice oxygen-based electrode materials with high-energy-density.

25 ENERGY STORAGE↗
DOE OSTI2023

Electrochemical-mechanical coupling failure mechanism of composite cathode in all-solid-state batteries

Composite cathode composed of active particles and solid electrolytes (SEs) can considerably enlarge the particle-SE contact areas and achieve high areal loadings in all-solid-state batteries (ASSBs). However, the challenging interfacial instability and particle damage problems remain unsolved. Herein, we establish a 3D electrochemical-mechanical coupled model to investigate the underlying failure mechanism by considering the governing electrochemical and physics processes. Micro-scale heterogeneous primary particles with random crystallographic orientation and size inside the LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM111) secondary particle of the model result in the anisotropic Li diffusion and volume variation within the secondary particle, leading to significant nonuniformity of the Li concentration, and GPa-level stress distributions at primary particle boundaries, and finally causing the particle internal cracks. The particle volume shrinkage under the constraint of stiff Li 7 La 3 Zr 2 O 12 (LLZO) SE triggers the interface debonding (gap>50 nm) with increased interfacial impedance to degrade cell capacity. Higher C-rates result in larger residual stress (~100 MPa)/strain/debonding gap at dis-charging end, more likely to deteriorate the cell performance. Increasing the interfacial strength between the particle and SE can suppress the interface debonding but induces high stress (up to 10 GPa). In conclusion, results reveal the underlying mechanism of the electrochemical-mechanical coupling failure mechanism for composite cathode and provide promising guidance on the further improvement of a more robust composite cathode for ASSBs.

25 ENERGY STORAGE↗
DOE OSTI2024

Progress in direct recycling of spent lithium nickel manganese cobalt oxide (NMC) cathodes

With the widespread use of lithium-ion batteries (LIBs) in portable electronics and electric vehicles (EVs), the end-of-life (EOL) LIBs are projected to reach 1336 GWh by 2040 under the sustainable development scenario. Proper recycling is urgently needed to minimize the release of hazardous waste and reduce mining activities by reintroducing critical minerals into the supply chain. Lithium nickel manganese cobalt oxide (LiNi x Mn y Co z O 2 , NMCs) cathodes have become dominant in the LIB market, especially with the increasing production of EVs, which are also the most valuable components in EOL LIBs. Unlike pyrometallurgical and/or hydrometallurgical methods, which convert spent NMCs into metals or metal compounds, direct recycling technologies aim to maximize the value of spent cathodes by restoring their degraded structure and composition. Furthermore, this review summarizes direct recycling methods for NMC cathodes published in the last decade and provides insights into the challenges and future development of direct recycling techniques.

Cathode↗
DOE OSTI2022

High-performance LiNi 0.8 Mn 0.1 Co 0.1 O 2 cathode by nanoscale lithium sulfide coating via atomic layer deposition

The commercialization of nickel-rich LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) has been hindered by its continuous loss of practical capacity and reduction in average working voltage. To address these issues, surface modification has been well-recognized as an effective strategy. Different from the coatings reported in literature to date, in this work, we for the first time report a sulfide coating, amorphous Li 2 S via atomic layer deposition (ALD). Here, our study revealed that the conformal nano-Li 2 S coating shows exceptional protection over the NMC811 cathodes, accounting for the dramatically boosted capacity retention from ~11.6% to ~71% and the evidently mitigated voltage reduction from 0.39 to 0.18 V after 500 charge–discharge cycles. In addition, the Li 2 S coating remarkably improved the rate capability of the NMC811 cathode. Our investigation further revealed that all these beneficial effects of the ALD-deposited nano-Li 2 S coating lie in the following aspects: (i) maintain the mechanical integrity of the NMC811 electrode; (ii) stabilize the NMC electrode/electrolyte interface; and (iii) suppress the irreversible phase transition of NMC structure. Particularly, this study also has revealed that the nano-Li 2 S coating has played some unique role not associated with traditional non-sulfide coatings such as oxides. In this regard, we disclosed that the Li 2 S layer has reacted with the released O 2 from the NMC lattices, and thereby has dramatically mitigated electrolyte oxidation and electrode corrosion. Thus, this study is significant and has demonstrated that sulfides may be an important class of coating materials to tackle the issues of NMCs and other layered cathodes in lithium batteries.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Liquid cadmium cathode performance model based on the equilibrium behaviors of U and Pu in molten LiCl–KCl/Cd system at 500°C

The liquid cadmium cathode is a pyroprocessing technology used for the recovery of group actinide metals from the molten chloride salts that support uranium electrorefining. This article presents a model for the performance of a liquid cadmium cathode based on considerations of salt/alloy equilibrium thermodynamics, Cd-U-Pu phase diagram behaviors, and mass balance constraints. In conclusion, the model demonstrates how the salt/cadmium system responds as incremental additions of uranium are made to the liquid cadmium cathode.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2013

Composite Organic Radical - Inorganic Hybrid Cathode for Lithium-ion Batteries

A new organic radical inorganic hybrid cathode comprised of PTMA/LiFePO4 composite system is developed and reported for the first time. The hybrid cathodes demonstrate high pulse power capability resulting in a significant improvement over the pure PTMA or LiFePO4 cathode which is very promising for transportation and other high pulse power applications that require long cycle life and lower cost.

high pulse power↗
DOE OSTI2022

A pseudo-two-dimensional (P2D) model for FeS 2 conversion cathode batteries

Conversion cathode materials are gaining interest for secondary batteries due to their high theoretical energy and power density. However, practical application as a secondary battery material is currently limited by practical issues such as poor cyclability. To better understand these materials, we have, for this study, developed a pseudo-two-dimensional model for conversion cathodes. We apply this model to FeS 2 – a material that undergoes intercalation followed by conversion during discharge. The model is derived from the half-cell Doyle–Fuller–Newman model with additional loss terms added to reflect the converted shell resistance as the reaction progresses. We also account for polydisperse active material particles by incorporating a variable active surface area and effective particle radius. Using the model, we show that the leading loss mechanisms for FeS 2 are associated with solid-state diffusion and electrical transport limitations through the converted shell material. The polydisperse simulations are also compared to a monodisperse system, and we show that polydispersity has very little effect on the intercalation behavior yet leads to capacity loss during the conversion reaction. Finally, we provide the code as an open-source Python Battery Mathematical Modeling (PyBaMM) model that can be used to identify performance limitations for other conversion cathode materials.

25 ENERGY STORAGE↗
DOE OSTI2024

High-entropy Li-rich layered oxide cathode for Li-ion batteries

High-entropy oxides (HEOs) are emerging as promising cathode materials for Li-ion batteries (LIBs) due to their stable solid-state phase and compositional flexibility. Herein, we investigate the structural and electrochemical properties of a novel non-equimolar high-entropy cathode material, termed high-entropy Li-rich layered oxide (HE-LLO, Li 1.15 Na 0.05 Ni 0.19 Mn 0.56 Fe 0.02 Mg 0.02 Al 0.02 O 1.97 F 0.03 ), in comparison to a pristine Li-rich layered oxide (PR-LLO, Li1.2Ni0.2Mn0.6O2). The incorporation of multiple cations (Na + , Al 3+ , Mg 2+ , Fe 3+ ) and anion (F - ) into HE-LLO introduces compositional diversity, enhancing structural stability through the entropy stabilization effect. Theoretical calculations confirm a significantly higher configurational entropy in HE-LLO compared to PRLLO, supporting its high-entropy nature. Electrochemical evaluations demonstrate that HE-LLO exhibits considerable capacity retention, preserving 76.8 % of its discharge capacity at 0.5C after 200 cycles, compared to only 36.2 % for PR-LLO. Even under high-temperature conditions, HE-LLO outperformed PR-LLO, maintaining 76.1 % of its discharge capacity after 100 cycles at 5C, while PR-LLO retained only 12.4 %. These enhancements are attributed to the improved phase reversibility and higher Li + ion diffusion coefficients of HE-LLO, validated by ex-situ characterizations using a synchrotron X-ray technique, along with density functional theory (DFT) calculations. In conclusion, these findings highlight the promise of non-equimolar HEOs as a novel design strategy for highperformance cathode materials.

25 ENERGY STORAGE↗
DOE OSTI2026

pCAM precursor produced from electroextraction technology and its application in synthesis of NMC 811 cathode material

The synthesis and characterization of LiNi 0.8 Co 0.1 Mn 0.1 O 2 (LNMC811) cathodes produced from recycled hydroxide precursors obtained from spent lithium-ion batteries is evaluated. Two precursor batches (Sample 1 and Sample 2) are prepared using modified recycling processes to examine how residual impurities and processing conditions influence the properties of the regenerated materials. Structural and compositional characterization by X-ray diffraction, ICP and SEM shows that the recycled precursors exhibit layered hydroxide structures containing both α Ni(OH) 2 and β Ni(OH) 2 phases. Trace impurities including sodium, boron, and aluminum are detected and partially mitigated during processing, with boron found to play a beneficial role in electrochemical behavior. Following lithiation with lithium carbonate and lithium hydroxide at 800 °C under an oxygen rich atmosphere, the resulting LNMC811 materials show electrochemical performance comparable to conventionally synthesized cathodes. Sample 2, which contains higher boron levels and improved cation ordering, delivers an initial discharge capacity of 174 mAh g -1 and retains more than 93 percent of its capacity after 50 cycles. The stable cycling behavior and structural integrity of these materials demonstrate that recycled precursors can be converted into high performance layered cathodes and support recycling as a practical and sustainable route for lithium-ion battery manufacturing.

25 ENERGY STORAGE↗
DOE OSTI2014

LiMn{sub 2}O{sub 4} nanoparticles anchored on graphene nanosheets as high-performance cathode material for lithium-ion batteries

Nanocrystalline LiMn{sub 2}O{sub 4}/graphene nanosheets nanocomposite has been successfully synthesized by a one-step hydrothermal method without post-heat treatment. In the nanocomposite, LiMn{sub 2}O{sub 4} nanoparticles of 10–30 nm in size are well crystallized and homogeneously anchored on the graphene nanosheets. The graphene nanosheets not only provide a highly conductive matrix for LiMn{sub 2}O{sub 4} nanoparticles but also effectively reduce the agglomeration of LiMn{sub 2}O{sub 4} nanoparticles. The nanocrystalline LiMn{sub 2}O{sub 4}/graphene nanosheets nanocomposite exhibited greatly improved electrochemical performance in terms of specific capacity, cycle performance, and rate capability compared with the bare LiMn{sub 2}O{sub 4} nanoparticles. The superior electrochemical performance of the nanocrystalline LiMn{sub 2}O{sub 4}/graphene nanosheets nanocomposite makes it promising as cathode material for high-performance lithium-ion batteries. - Graphical abstract: Nanocrystalline LiMn{sub 2}O{sub 4}/graphene nanosheets (GNS) nanocomposite exhibit superior cathode performance for lithium-ion batteries compared to the bare LiMn{sub 2}O{sub 4} nanoparticles. Display Omitted - Highlights: • LiMn{sub 2}O{sub 4}/graphene nanocomposite is synthesized by a one-step hydrothermal method. • LiMn{sub 2}O{sub 4} nanoparticles are uniformly anchored on the graphene nanosheets. • The nanocomposite exhibits excellent cathode performance for lithium-ion batteries.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Morphological effects on the electrochemical performance of lithium-rich layered oxide cathodes, prepared by electrospinning technique, for lithium-ion battery applications

Li-rich Li{sub 1.2}Ni{sub 0.17}Co{sub 0.17}Mn{sub 0.5}O{sub 2} cathode materials were synthesized by electrospinning technique with different polymers, and their structural, morphological, and electrochemical performances were investigated. It was found that the electrospinning process leads to the formation of a fiber and flower-like morphology, by using different polymers and heat treatment conditions. The nanostructured morphology provided these materials with high initial discharge capacity. The cycling stability was improved with agglomerated nano-particles, as compared with porous materials. - Highlights: • Fiber and flower-like Li-rich cathode was synthesized by simple electrospinning. • Polymer dependent morphology and electrochemical performance was investigated. • Well-organized porous structure facilitates the diffusion of lithium ions. • Technique could be applicable to other cathode materials as well.

36 MATERIALS SCIENCE↗
DOE OSTI2011

High rate performances of the cathode material LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2} synthesized using low temperature hydroxide precipitation

Graphical abstract: A low-temperature reaction route is introduced based on hydroxide precipitation method to synthesize a cathode material LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2}. The charge-discharge tests were performed at 1000 mA g{sup -1} between 2.5 and 4.5 V and the discharge capacity is about 160 mAh g{sup -1}. The discharge capacity of the material is strongly impacted by the reaction temperature. The powders sintered at 850 {sup o}C show the best electrochemical performance. Highlights: {yields} A low-temperature reaction route is introduced based on hydroxide precipitation method to synthesize a novel cathode material LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2}. {yields} The charge-discharge tests were performed at higher current as 5 C between 2.5 and 4.5 V. {yields} The discharge capacity of the material is strongly impacted by the reaction temperature. The powders sintered at 850 {sup o}C show the best electrochemical performance. -- Abstract: A low-temperature reaction route is introduced based on hydroxide precipitation method to synthesize the cathode material LiNi{sub 1/3}Co{sub 1/3}Mn{sub 1/3}O{sub 2}. The crystal structure and morphology of the prepared powder have been characterized by X-ray diffraction and Scan electron microscope, respectively. The charge-discharge tests were performed between 2.5 and 4.5 V. The discharge capacity of the material is strongly impacted by the reaction temperature. The powders sintered at 850 {sup o}C show the best electrochemical performance and the initial discharge capacity is about 160 mAh g{sup -1} at 5 C. Powder X-ray diffraction and Scan electron microscope results reveal that the excellent electrochemical performances should be ascribed to the lower precursor reaction temperature, the lower degree of cation mixing and analogous spherical small particles, which can improve the transfer of Li ions and electrons. All these results indicate that this material has potential application in lithium-ion batteries.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al{sub 2}O{sub 3} can provide surface area for the deposition of Li{sub 2}S and Li{sub 2}S{sub 2}. ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g{sup −1}, and the remaining capacity was 585 mAh g{sup −1} after 50 cycles at 0.25 mA cm{sup −2}. Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Comparisons of short carbon nanotubes containing conductive additives of cathode for lithium ion batteries

Graphical abstract: - Highlights: • Short carbon nanotubes (SCNT) containing conductive additives were used. • SCNT/graphite powder (GP) mixture is better than SCNT/mesoporous carbon mixture. • SCNT connect many isolated GP particles to form a more valid conductive network. • SCNT absorb some electrolyte solution allowing quick electrochemical reactions. - Abstract: Short carbon nanotubes (SCNT) containing conductive additives, i.e. SCNT/graphite powder (GP) mixture (SCNTGP) and SCNT/mesoporous carbon (MC) mixture (SCNTMC) were employed as conductive additives for LiCoO{sub 2} cathode. GP and MC have similar particle size, but GP has lower specific surface area and higher electronic conductivity. Electrochemical measurements indicate that SCNTGP is more effective in improving the electrochemical performance of LiCoO{sub 2} composite cathode under the same conditions. The reason is described as follows. SCNT connect the isolated GP particles to form a more valid conductive network. In addition, SCNT has a certain specific mesoporous surface area, which can absorb some electrolyte solution and then provide buffer lithium ions for quick electrochemical reactions. Consequently, the combination of these two factors would be responsible to the improvement in the electrochemical performance of the SCNTGP loaded cathode.

36 MATERIALS SCIENCE↗
DOE OSTI2014

One-step synthesis of dense and spherical nanostructured V{sub 2}O{sub 5} particles for cathode of lithium batteries and their electrochemical properties

Graphical abstract: Dense and spherical nanostructured V{sub 2}O{sub 5} particles. - Highlights: • One-step synthesis of dense, spherical, nanostructured V{sub 2}O{sub 5} particles was achieved. • As-prepared V{sub 2}O{sub 5} consists of primary particles of approximately 100 nm size. • The electrochemical performance of spherical nanostructured V{sub 2}O{sub 5} was investigated. • The potential range affects to the discharge capacity and cyclability of V{sub 2}O{sub 5}. - Abstract: A one-step synthesis of V{sub 2}O{sub 5} was directly achieved via ultrasonic spray pyrolysis at various synthesis temperatures ranging from 500 to 700 °C. The V{sub 2}O{sub 5} prepared at 500 °C is dense and spherical nanostructured particles, which consist of primary particles with a size of approximately 100 nm. The morphology change remarkably progresses with increasing synthesis temperatures from 500 to 700 °C. The electrochemical performance of a cathode comprising dense and spherical nanostructured V{sub 2}O{sub 5} particles prepared at 500 °C was investigated by galvanostatic discharge–charge cycling and cyclic voltammetry. From the discharge–charge cycling, the initial discharge capacity of the cathode was found to be about 403 mAh g{sup −1} in the potential range of 1.5–4.0 V, but it decreased owing to inherent phase changes with repeated cycling. The potential range significantly affects the cycle performance, and the V{sub 2}O{sub 5} cathode showed good cycle performance in the potential range of 2.5–4.0 V.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Novel mixed hydroxy-carbonate precursor assisted synthetic technique for LiNi{sub 1/3}Mn{sub 1/3}Co{sub 1/3}O{sub 2} cathode materials

Highlights: • MHC method used to overcome drawbacks of solid state synthesized materials. • Least cation mixing, phase purity, good reversibility and rate capability achieved. • XRD I {sub 0} {sub 0} {sub 3}/I{sub 1} {sub 0} {sub 4} factor, indicating electrochemical reactivity is maximum at 1.6984. • Li/LiNi{sub 1/3}Mn{sub 1/3}Co{sub 1/3}O{sub 2} cell delivered an initial discharge capacity of 175 mAh g{sup −1}. - Abstract: Novel mixed hydroxy-carbonate (MHC) precursors were used to synthesis technique of LiNi{sub 1/3}Mn{sub 1/3}Co{sub 1/3}O{sub 2} cathode material. The powder X-ray diffraction (XRD) pattern of the synthesized LiNi{sub 1/3}Mn{sub 1/3}Co{sub 1/3}O{sub 2} cathode materials exhibited a hexagonal cell with a = 2.8535 Å and c = 14.2040 Å. Fourier transform infrared spectroscopy (FT-IR) spectrum of MHC and LiNi{sub 1/3}Mn{sub 1/3}Co{sub 1/3}O{sub 2} consistent with vibration modes of functional group. Presence of sub-micrometer particle size (200 nm) and highly crystalline morphology confirmed using scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) suggested that oxidation state of the transition metals; Ni in +2, Mn in +4 and Co in +3 states, respectively in LiNi{sub 1/3}Mn{sub 1/3}Co{sub 1/3}O{sub 2} cathode materials. Cyclic voltammograms (CV) revealed only one major redox couple at 4 V and suggested the absence of structural transitions from hexagonal to monoclinic structure. The Li vs. LiNi{sub 1/3}Mn{sub 1/3}Co{sub 1/3}O{sub 2} cell delivered an initial discharge capacity of 175 mAh g{sup −1} in the voltage range 2.5–4.6 V @ 0.1 C.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Nanoparticle-assembled LiMn{sub 2}O{sub 4} hollow microspheres as high-performance lithium-ion battery cathode

Highlights: • The LiMn{sub 2}O{sub 4} hollow microspheres are assembled by LiMn{sub 2}O{sub 4} octahedral nanoparticles. • The LiMn{sub 2}O{sub 4} hollow microspheres exhibit larger diffusion coefficient and better rate performance. • The LiMn{sub 2}O{sub 4} hollow microspheres display longer cycling stability. - Abstract: Spinel LiMn{sub 2}O{sub 4} is an attractive cathode material for rechargeable lithium-ion batteries. However, its cycling and rate performance need further improvement. Herein, we present a novel LiMn{sub 2}O{sub 4} hollow microsphere cathode fabricated via a simple solid-state reaction utilizing MnO{sub 2} hollow microspheres and LiOH·H{sub 2}O as the reactants. Interestingly, the as-prepared LiMn{sub 2}O{sub 4} hollow microspheres are assembled by LiMn{sub 2}O{sub 4} octahedral nanoparticles with exposed {111} planes, exhibiting abundant void spaces for the stress buffering and larger diffusion coefficient (1.570 × 10{sup −7} cm{sup 2} s{sup −1}) for fast lithium ion transfer as compared to the simply aggregated LiMn{sub 2}O{sub 4} nanoparticles. As a result, the LiMn{sub 2}O{sub 4} hollow microspheres exhibit much improved cycling stability and deliver a specific discharge capacity of 86.3 mAh g{sup −1} at a high rate of 10C, higher than that of the aggregated LiMn{sub 2}O{sub 4} (73.9 mAh g{sup −1}). Our work suggests that the electrochemical performance of LiMn{sub 2}O{sub 4} cathode can be manipulated by the design of unique hollow sphere structure.

36 MATERIALS SCIENCE↗