Silica Restricting the Sulfur Volatilization of Nickel Sulfide for High‐Performance Lithium‐Ion Batteries

Abstract

are important factors. More efforts are required to develop low-cost and efficient electrode materials. [4,5] As an important part of battery components, anode materials have been one of the most critical and extensively studied aspects in electrochemical research. [6][7][8][9][10] Among the many anode materials, transition metal-based compounds are characterized as a promising species due to their abundant reserves and multiple valence nature. Having more electrons involved in electrochemical reactions can provide higher capacity that meet the energy density requirements of modern electrochemical storage devices. [11,12] In this regard, many efforts have been made to discover new transition metal-based anode materials such as carbides, oxides, phosphides, or sulfides. [13][14][15] Due to its abundance and low prices, mineral-type nickel sulfide has gained much attention in photo-electrochemistry and is widely used in semiconductor, magnetic, photo-electrocatalytic, thermoelectric, phase-converting materials, and electrode materials for rechargeable lithium-ion batteries. [16][17][18][19][20] In prior research, the numerous nickel sulfides applied in rechargeable lithiumion batteries (NiS, NiS 2 , Ni 3 S 2 , and Ni 3 S 4 ) have all possessed high theoretical capacities (NiS/589, NiS 2 /870, Ni 3 S 2 /445, and Ni 3 S 4 /703 mAh g −1 ). [20] However, nickel sulfides are seldom regarded as excellent candidates for lithium-ion batteries, mainly due to the instability in the nickel-rich active material. As a result, during lithiation and delithiation the active materials tend to be more susceptible to pulverization and collapse, making it difficult to form a stable interface. The everexpanding interface area between active materials and electrolyte will continuously consume Li + to form the solid electrolyte interface (SEI), resulting in low coulombic efficiency. Meanwhile, the electrically insulated SEI layer will wrap the active materials to form "inactive island" which results in rapid capacity decay and poor cycle performance. [21,22] Numerous strategies have been developed to address this issue, such as controlling cutoff voltage, [20] constructing nanomaterials, [21] and compositing with graphene. [23,24] However, despite extensive research efforts, improving the performance of nickel sulfide to achieve high specific capacity and long cycle life is still a challenge. [21,25,26] Herein, a step-divided construction method was developed successfully to synthesize the NiS x @carbon (NiS x @C) yolk-shell microboxes via a template-assisted coating, thermal Nickel sulfides are regarded as promising anode materials for advanced rechargeable lithium-ion batteries due to their high theoretical capacity. However, capacity fade arising from significant volume changes during operation greatly limits their practical applications. Herein, confined NiS x @C yolk-shell microboxes are constructed to address volume changes and confine the active material in the internal void space. Having benefited from the yolk-shell structure de...

Preparation of cobalt sulfide@reduced graphene oxide nanocomposites with outstanding electrochemical behavior for lithium-ion batteries

“…Recently, various transition metal suldes (MS x ) such as FeS x , 7 NiS x , 8,9 MnS x , 10 MoS 2 , 11,12 SnS 2 , 13 CuS, 14,15 ZnS 16 have been fabricated and served as anode materials for LIBs due to their high theoretical capacities, low cost and abundant raw materials.…”

Improving the Cycling Stability of Fe3O4/NiO Anode for Lithium Ion Battery by Constructing Novel Bimodal Nanoporous Urchin Network

“…It should be mentioned that compared to traditional graphite anodes (90 wt.% + active material), the transition metal oxide-typed anodes inevitably contain a lower proportion (70 wt.% in this study) of active material in the overall electrode composition, which affects the real achievable capacity of the whole electrode to a certain degree. In the initial reduction process, the sample shows two reduction peaks near 0.8 V and 0.6 V. The peak at 0.8 V corresponds to the reduction of NiO to Ni [29] and the peak at 0.6 V is related to the reduction of Fe 3+ or Fe 2+ to Fe 0 [30]. The two reduction peaks move to about 1.56 V and 0.76 V in the later cycles.…”

“…The difference in the peak position and peak intensity between the first cycle and the following cycles can be attributed to the formation of a solid electrolyte interface (SEI) layer and the structural modification of Li + drive during the lithiation process [26]. In the first anodic scan, the broad peak in the range of 1.1-1.7 V can be ascribed to the step-by-step oxidation of Fe 0 to Li x Fe 3 O 4 and Fe 3+ , respectively [30]. The peak at 2.3 V corresponds to the oxidation of Ni to NiO [29].…”

“…Figure 5 a reveals the CV curves of the DA-24 sample testing at a scan rate of 0.1 mV s −1 in a voltage range of 0.01–3 V. In the initial reduction process, the sample shows two reduction peaks near 0.8 V and 0.6 V. The peak at 0.8 V corresponds to the reduction of NiO to Ni [ 29 ] and the peak at 0.6 V is related to the reduction of Fe 3+ or Fe 2+ to Fe 0 [ 30 ]. The two reduction peaks move to about 1.56 V and 0.76 V in the later cycles.…”

“…The EIS consists of two parts including the high and medium frequency region (semicircle) caused by charge transfer resistance and the low-frequency region (slash) because of ion diffusion. Obviously, the electrode presents lower resistance and better conductivity after cycling, which may possibly be due to structural rearrangement of surface elements and the formation of the stable SEI layer [ 30 ] during cycling process. As shown in the insert of Figure 6 d, in order to evaluate the possibilities of the as-prepared Fe 3 O 4 /NiO electrode in practical application, we put a battery in series with an LED bulb (0.1 W, 3 V).…”