Query: lithium battery in situ

title: In situ formation of hybrid Li3PO4 AlPO4 Al(PO3)3 coating layer on LiNi0.8Co0.1Mn0.1O2 cathode with enhanced electrochemical properties for lithium ion battery
abstract: Irreversible phase transition and surface residual lithium, which cause the fast capacity fading of LiNi0.8Co0.1Mn0.1O2 (NCM811) are the main obstacles that hinder their commercial application. Herein, to modify the surface/interphase properties of NCM811, we elaborately propose a hybrid Li3PO4 AlPO4 Al(PO3)3 coating layer that combines the advantages of ionic conductor (Li3PO4) and thermal stable compound (AlPO4) via reacting aluminum metaphosphate (Al(PO3)3) precursor with the surface residual lithium (Li2CO3 or/and LiOH) during the coating process. When used as cathode for lithium ion battery, the optimized NCM811 delivers a high initial discharge capacity of 201.8 mAh g 1 and 218.9 mAh g 1 at 0.1C under the temperature of 30 degC and 50 degC, with capacity retention of 85.4% and 78.89% after 50 cycles, respectively, which are much higher than that of uncoated sample (73.93% and 57.98% Moreover, when it is coupled with graphite anode to form a lithium ion full cell, it delivers an impressively high energy density of 467.5 Wh kg 1 (based on mass of positive and negative material) and retains 71.8% of its initial energy density after 100 cycles. The significantly enhanced electrochemical properties should be attributed to the multifunctional hybrid nano coating layer that could efficiently reduce the surface residual lithium, suppress the irreversible phase transition, and prevent the active materials from the erosion of HF as verified by the ex situ X ray diffractometry, Raman spectroscopy and transmission electron microscopy. This work provides new insights into the surface/interphase design strategies to improve the structural stability of Ni rich cathode, which will promote the development of high capacity cathode materials.

title: In situ sol gel synthesis of Ti2Nb10O29/C nanoparticles with enhanced pseudocapacitive contribution for a high rate lithium ion battery
abstract: Ti2Nb10O29/C nanoparticles with a carbon content of 13 wt% and a mean size of 50 nm were fabricated through a convenient and effective in situ sol gel process. The small grain size and carbon modification can improve the pseudocapacitive effect of the Ti2Nb10O29/C nanoparticles, leading to excellent rate capacity, especially at high current rate. Specifically, the discharge capacity of the Ti2Nb10O29/C electrode is 258.3, 236.0, 216.6, 184.5 and 161.5 mAh*g 1 at different current densities of 1C, 5C, 10C, 20C and 30C. Nevertheless, the discharge capacity of the Ti2Nb10O29 electrode is 244.9 mAh*g 1 at 1C, which is rapidly reduced to 89.7 mAh*g 1 at 30C. In addition, the small size and carbon layer of the Ti2Nb10O29/C nanoparticles can supply abundant active sites for Li+ storage as well as enhance the electronic conductivity and Li+ diffusion, endowing these nanoparticles with a high discharge capacity and excellent cycle performance.

title: Solid State Battery Interface: In Situ Direct Lithium Distribution Analysis Around Interfaces in an All Solid State Rechargeable Lithium Battery by Combined Ion Beam Method (Adv. Mater. Interfaces 14/2019)

title: In situ assembly of TiO2 with high exposure of (001) facets on three dimensional porous graphene aerogel for lithium sulfur battery
abstract: Resulting from the development of electric vehicles, high energy density Li S batteries have recently attracted ever increasing attentions worldwide. However, continuous dissolution of cathodic sulfur and followed shuttle effect of polysulfides lead to very limited service lifetime for currently applied Li S batteries. Herein, a 3D porous graphene aerogel (GA) decorated with high exposure of anatase TiO2(001) nanoplatelets is proposed as robust host to immobilize cathodic sulfur. Compared with commonly used TiO2(101) nanoparticles, the TiO2(001) nanoplatelets have highly matched lattices with graphene (002) nanosheets, thus facilitating the electronic transfer. The in site assembled TiO2@GA host exhibits superior sulfur immobilized capability, which cannot only entrap sulfur by physical confinement, but also capture dissoluble sulfurous species by chemical bonding. The fabricated S@TiO2@GA cathode shows excellent electrochemical performance with high discharge capacity, superior rate capability, and durable cycling stability as well, supposed to be a promising cathode for high performance Li S battery applications.

title: Promoting performance of lithium sulfur battery via in situ sulfur reduced graphite oxide coating
abstract: Activated graphene/sulfur structure sheathed in a flexible graphene layer is presented as the cathode material of lithium sulfur battery. The surface coating graphite oxide sheets are reduced by a one step in situ sulfur reduction method under vacuum at 600 degC without any additional reductant. The high reduction degree of in situ sulfur reduced graphite oxide (RGO) coating layer will facilitate the rapid charge transfer at high current rate. The flexible encapsulated RGO structure will retard the diffusion of polysulfides and adjust the volume change of sulfur in cycling. As a result, the electrochemical evaluation of the RGO activated graphene (AG)/S electrode demonstrates superior capacity, cycling and rate performance. The RGO AG/S electrode with 60 wt% sulfur loading achieves a stable cyclability over 2000 galvanostatic charge/discharge process (capacity fade rate of only 0.03% per cycle at 1600 mA*g 1) The average Coulombic efficiency remains at 96% with no electrolyte additives (such as LiNO3) The outstanding property of RGO AG/S electrode is attributed to the distinctive in situ sulfur RGO coated hierarchical texture.

title: Probing Li ion concentration in an operating lithium ion battery using in situ Raman spectroscopy
abstract: In situ Raman spectroscopy was employed to probe Li ion concentration in liquid electrolytes at the cathode LiFePO4 particle surface in an optically transparent lithium ion battery. A Raman laser beam size of 2 mm was utilized so that Li ion transport dynamics at the particle level could be revealed. The variation of Li+ concentration in the LiPF6/ethylene carbonate (EC) dimethyl carbonate (DMC) electrolyte was experimentally determined by analyzing Raman peaks corresponding to the C O stretching vibration in EC and its relative intensity as to the Li+ solvent interaction in solvated products. The electrolyte concentration at the LiFePO4 particle surface was found to fluctuate during a battery charge discharge cycle. Particularly, near the end of battery discharge, it reached to a minimum value (0.23 M) which was far less than its initial balanced value (1 M)

title: In situ implanted carbon nanofilms into lithium titanate with 3D porous structure as fast kinetics anode for high performance dual ion battery
abstract: Dual ion battery (DIB) paring lithium titanate (LTO) anode with graphite cathode is attractive for energy storage applications owing to its merits of environmental friendly, excellent cyclic stability, and good safety. However, the specific capacity of the LTO DIB is still relatively low

title: In situ visualization of lithium plating in all solid state lithium metal battery
abstract: Lithium metal with high theoretical specific capacity (3860 mAh/g) and the lowest electrochemical potential 3.04 V vs standard hydrogen electrode) has been considered as the most promising anode material for next generation rechargeable batteries. Since lithium readily reacts with most organic solvents, complete replacement of conventional electrolytes with solid electrolyte has attracted much attention. However, in solid state lithium batteries uncontrollable lithium dendrites growth and large interface fluctuations during lithium plating/stripping still happens, leading to short circuit or capacity fading. This study employs Neutron Depth Profile (NDP) a unique tool with high sensitivity and high spatial resolution for lithium detection in solid device, to investigate the lithium plating behavior in Li|Li6.4La3Zr1.4Ta0.6O12 (LLZTO)|Ti solid state battery with three dimensional (3D) Ti electrode. The experiments, together with theoretical modeling, show that the majority of lithium can be deposited in the void space of the Ti 3D electrode which largely diminishes solid electrolyte/electrode interface degradation and suppresses lithium dendrite growth as well. This research demonstrates that a negative electrode with efficiently designed 3D framework can not only undertake the huge volume expansion during lithium plating but also regulate lithium deposition behavior to inhibit Li dendrite growth.

title: In Situ Self Formed Nanosheet MoS3/Reduced Graphene Oxide Material Showing Superior Performance as a Lithium Ion Battery Cathode.
abstract: Although lithium sulfur (Li S) batteries have 5 10 times higher theoretical capacity (1675 mAh g 1) than present commercial lithium ion batteries, Li S batteries show a rapid and continuous capacity fading due to the polysulfide dissolution in common electrolytes. Here, we propose the use of a sulfur based cathode material, amorphous MoS3 and reduced graphene oxide (r GO) composite, which can be substituted for the pure sulfur based cathodes. In order to enhance kinetics and stability of the electrodes, we intentionally pulverize the microsized MoS3 sheet into nanosheets and form an ultrathin nano SEI on the surface using in situ electrochemical methods. Then, the pulverized nanosheets are securely anchored by the oxygen functional group of r GO. As a result, the electrochemically treated MoS3/r GO electrode shows superior performance that surpasses pure sulfur based electrodes; it exhibits a capacity of about 900 mAh g 1 at a rate of 5C for 2500 cycles without capacity fading. Moreover, a full cell battery employing the MoS3/r GO cathode with a silicon carbon composite anode displays a 3 5 times higher energy density (1725 Wh kg 1/7100 Wh L 1) than present LIBs.

title: In situ synthesis of a silicon flake/nitrogen doped graphene like carbon composite from organoclay for high performance lithium ion battery anodes.
abstract: A silicon flake/nitrogen doped graphene like carbon composite was prepared from organoclay via an in situ strategy, involving carbonization followed by low temperature aluminothermic reduction. The pre formed carbon sheets within the confined interlayer space of clay acted as nanotemplates for in situ synthesizing silicon flakes. As a lithium ion battery anode, the composite exhibited excellent electrochemical properties.