Li-ion Batteries

Li-ion batteries  are under constant challenge to improve performance and reduce cost by material and process developments. Since its introduction, the cost/performance has steadily improved  by  8 % per year over a period of 20 years, a process that still continues. Currently,  challenges in Li-ion batteries are  i) cycle life at deep discharge, ii) safety,   iii) the high cost.  Efforts at ENDAM  within this framework concentrates on both cathode and anode materials

        
XRD Pattern of   NCA compound                                    SEM micrograph of  NCA compound synthesized
through sonochemical processing

Cathode Materials: Activities  at ENDAM on cathode materials have   centered on layered transition metal oxide as they have   enhanced  kinetics. Thermal and structural stability  have been  addressed via alloying  both in NMC  and NCA  compounds. Optimized chemistry  yielded an improved capacity retention.  NMC and NCA preserved their 65 % and 72 % of capacity during cycling at ( 1C). Applying recovery cycling at  a slow rate improved this  values   up to 99 % (NMC). The value in the case of NCA was   93 % .

.SEM Micrograph of NMC compounds             Capacity retention in NMC and NCA cathodes
…………………..     …………………………………………….at different discharge rate

Anode Materials  Activities at ENDAM  on anode materials covers graphite, silicon as well as tin.  Currently work is in progress to develop graphitic materials with controlled interlayer disctance as as to enhance high rate  dischargeability. In the case of silicon and tin, the aim is to develop  carbon encapsulated active materials so as to improve the conductivity and the integrity of the anode material.