Surface homogenizing heterostructure coatings induced by Ti ₃ C ₂ T _x MXene for enhanced cycle performance of lithium‐rich cathode materials

Abstract

Summary The layered lithium‐rich manganese‐based cathode material (Li1.2Mn0.54Co0.13Ni0.13) has the significant advantage of high specific capacity, but this material also suffers serious defects, including severe capacity attenuation and voltage attenuation during the cycle. At present, most researchers have been working to optimize the cycle performance of lithium‐rich materials. In this work, we propose a surface homogenizing heterostructure coating induced by MXene modification to reduce capacity reduction and voltage decay. It can be found that the initial Coulombic efficiency (ICE) increases from 77.2% for the bare electrode Li1.2Mn0.54Co0.13Ni0.13 (LMO) to 85.5% for 1.4 wt% MXene (Ti3C2Tx, Tx represents the surface terminations: OH, O, F) modified lithium‐rich (TO2). Furthermore, the discharge specific capacity of the electrode at 5 C rate increased from 160.7 mAh g−1 for LMO to 200.6 mAh g−1 for TO2. More prominently, the outstanding cycle stability with capacity retention rate is 82.1% for TO2 after 200 cycles, while only 64.7% for LMO, and the average discharge voltage dropped from 0.788 to 0.468 V. In addition, the mechanism for improving the electrochemical performance is systematically studied.

A review on the stability and surface modification of layered transition-metal oxide cathodes

“…Defining the chemical/physical/structural changes of the outer and inner surfaces as surface modification, three types can be categorized: (1) surface coating, the dominant strategies, including electrochemically inactive compounds coating (e.g., metal oxides, fluorides, and phosphates) [34][35][36][37][38], Li impurities-reactive coating (Co 3 O 4 ) [39] and Li-reactive coating (MoO 3 ) [40], Li ion conductive coating (LiTi 2 O 4 , Li 2 ZrO 3 and Li 4 -Mn 5 O 12 ) [41][42][43], conducting polymer coating (e.g., polypyrrole (PPy), polyaniline (PANI) and poly (3,4-ethylenedioxythiophene) (PEDOT)) [44][45][46], and other materials coatings, such as MXene (e.g. Ti 3 C 2 T x ) [47] and conductive graphene matrix [48]; (2) gradient structure design, including core-shell structures [49][50][51][52], hierarchical architectures (i.e., multi-shell) [53][54][55], and concentration gradient (CG) structures [56][57][58]; and (3) other surface treatments, such as rinsing with water to form an oxygendepleted surface layer [59,60], utilizing atomic surface reduction to alter the electronic structure of the surface [61], and surface doping to form an enriched extrinsic ions surface [62].…”

Recent Advancements in Battery Management System for Li‐Ion Batteries of Electric Vehicles: Future Role of Digital Twin, Cyber‐Physical Systems, Battery Swapping Technology, and Nondestructive Testing

“…In addition, the strain gradient of the cell was also determined. Li et al [ 29 ] designed and studied an effective cooling system for battery packs based on thermoelectric generator coupled with forced convection. [ 29 ] The study resulted in an approximate 16.66% reduction in battery temperature even at a higher discharging rate.…”

Role of SEI layer growth in fracture probability in lithium‐ion battery electrodes

“…Plugging Equations (22) to (24) into Equation (25) yields the following partial differential equation for the radial displacement:…”

“…Using these boundary conditions, the radial displacement u(r, t) is solved from Equation (27). Furthermore, plugging u into Equations (22) to (24) gives the radial and tangential stresses inside the core as:…”

“…20,21 However, these properties are difficult to evaluate due to the complex and varied chemical composition of the SEI. [22][23][24] Researchers have found that the SEI layer can be formed in single, double, multilayer, 25,26 porous, 27 and sandwich structures. 28 Experimental findings reported that the SEI layer on the carbon electrode could be brittle 29 or elastic.…”